Vettel’s tyre failure due to Ferrari strategy – Pirelli

2015 Belgian Grand Prix

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Pirelli motorsport director Paul Hembery says Sebastian Vettel’s tyre blow-out at the end of the Belgian Grand Prix was caused by high wear owing to his long stint on the rubber.

A furious Vettel said the failure, which cost him a potential podium finish, was “unacceptable”. However Hembery said the team had taken a risk by running on the tyre for so long.

“It was at the end of wear life,” Hembery told reporters after the race, “so when you do that, any tyre in the world when it gets to the end of its wear life you’re going to have a problem”.

Hembery said Pirelli were expecting most teams to run two or three stop strategies. “But [Ferrari] felt clearly that they could make it work on a one-stop.”

Vettel had done 28 laps on his set of medium tyres when the right-rear failed on the penultimate lap. “The wear life is indicated at around 40 laps but it’s an indication,” said Hembery.

“Race conditions can change that. Some factors involved in racing means sometimes that’s not a precise datum. Other teams were clearly taking a different direction.”

“If the race had been one lap less he’d have been on the podium and we’d say what a genius move,” he added, “so that’s tough.”

Hembery also denied that Vettel’s failure was similar to the one experienced by Rosberg on Friday. “Rosberg was an external cut,” he said. “This was pure wear.”

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    Keith Collantine
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    146 comments on “Vettel’s tyre failure due to Ferrari strategy – Pirelli”

    1. If the tyres can last 40 laps why one-stop is not possible? I don’t understand that one.

      1. Because the conditions in the race. And you are driving at SPA, a track where the front tyres, particularly the front left, takes a lot of punishment. Another thing to note, is how much the driver is influencing on the tyre condition by his driving style. It does not mean that Pirelli say 40 laps, a tyre can last 40 laps doing normal race stints, that would be ridiculous here in SPA. In this case, the right rear got blown away, which I do find it weird since this is a clockwise circuit meaning that it should be the left rear that should take the wear and not the right rear.

        1. @krichelle

          It does not mean that Pirelli say 40 laps, a tyre can last 40 laps doing normal race stints, that would be ridiculous here in SPA.

          Then why did Pirelli say 40 laps for this race? It’s not like Pirelli said that a 10 races ago for Australia. Expected tyre life is estimated for each race for this very reason :/

          1. That would be ridiculous even though I watched Hembrey’s interview with Ted on SKY, they will surely analyze why Sebastian’s tyre explode. And come to think of that, this is what is weird:
            In this case, the right rear got blown away, which I do find it weird since this is a clockwise circuit meaning that it should be the left rear that should take the wear and not the right rear.

            1. @krichelle I don’t see how the italicised part of that post is weird (on a clockwise track the lefts are more often the outside, stress-bearing tyres than the left, no?)

        2. @krichelle, EXACTLY!!!

          I don’t understand why people are struggling with the 40 laps. My car has a rating of 28 MPG. Does that mean I will always get that? Of course not! Who here thinks they are actually going to get their manufacturer published MPG ratings all the time?

          You have to drive very conservatively to get that. Same with tires and Vettel was pushing hard to maintain his podium spot when his tire failed. Total opposite of conservative.

          1. @sudd

            My car has a rating of 28 MPG. Does that mean I will always get that

            This comment clearly show that all of your posts regarding the blow up are just jokes

          2. @sudd Your car isn’t designed not to be driven conservatively. You car isn’t designed by the (supposedly) very best engineers on the field. You car is not a F1 car, what it does or stops doing is irrelevant.

          3. Pirelli need a lot of explanation on why they say the wear is 40 laps on Medium Tyres at SPA. 40 laps is just absurd to do. By how I was looking at the interview with Ted Kravitz, it did seem like Paul did not care about how he was answering, he looked fed up or like “come on guys.. seriously”

            1. @krichelle

              By how I was looking at the interview with Ted Kravitz, it did seem like Paul did not care about how he was answering, he looked fed up or like “come on guys.. seriously”

              It was like that in the BBC, too. I wonder if he just stopped caring.

          4. @sudd Let’s say an airplane fails to make it to its destination due to the higher-than-given-by-maker fuel consumption.

            Do you expect an argument like “Well, Car MPGs are wrong so why shouldn’t such problems exist in aviation?” to work?

            1. @davidnotcoulthard, you see I live in the real world. So I tend to use real world analogies that occur normally and are testable and repeatable.

              What I don’t do is conjure up far fetched fantasies to use as defense.

              But to answer your fantasy, YES! That is why we have fuel gauges and planes fly with reserve tanks. Are you familiar with something called “margin of error.”

              Lets say a car or plane is rated at X MPG. In what universe are air planes and cars filling up exactly to the X amount, not a drop more or less of fuel and then throwing fits when they fail to reach their suggested range to the T?

            2. @sudd In my world, I can’t tolerate 30% off margin of error….

            3. @ruliemaulana Agreed. I’ve never seen a margin of error like 30%. This is a serious issue. Shouldn’t be swept under the rug. It could have been a catastrophe.

            4. @sudd A margin of error of 10% would probably not be allowed in a real-world science lab (which is not less real-world than F1, by the way!). And {100%(40-27)/40}>10% by quite a bit!

              What I don’t do is conjure up far fetched fantasies to use as defense.

              What I didn’t do is use flawed irrelevant analogies, which the MPG analogy is due to the fact that while it’s not that important for the well-being of people for MPGs to be accurate (filling up more often perhaps having expected so having read Autocar/express before buying the car), it’s important in F1 for tyre life estimation to be absolutely accurate, just like it is for aircraft fuel and weight balance to be very accurate (and by the way, my analogy was not a far-fetched fantasy – operating airplanes involve the kind of expectation of spec numbers (and expected tyre life, parts life, etc) to be right that F1 also has of specs and tyre life, etc to be right which operating a car doesn’t involve, making your analogy irrelevant and honestly far-fetched in terms of how far it is from what you’re trying to prove with it).

              This is because large inaccuracies in car MPG test results are far less catastrophic than a slight miscalculation or corner-cutting in F1 or aviaton (civil or otherwise) (the latter having resulted in planes crashing due to weight balance problems or Silverstone 2013, while the former in more cashflow and magazine opinion pieces regarding MPG).

        3. Pirelli might not recommend a one stop because they don’t think it is a competitive strategy (too slow), not because they think it is unsafe.

        4. right rear at Spa due to pouhon and blanchimont

      2. @michal2009b they didn’t say tyres can last 40 laps, they said that the tyre life is indicated at 40 laps, which isn’t the same. An indication acts as a recommendation, it’s not a fact. No car works the same way on tyres, and no driver wear down tyres the same way. Besides you have track conditions, weather… an indication should be taken as a recommendation by the manufacturer, doesn’t mean you have to follow it, but you have to be wary that anything different could alter the effectivity of the product, the way it behaves and how long it lasts.

        Like the extreme camber values in 2011. The tyre could work with higher angles, but they won’t work properly and nothing is guaranteed once you reach that point.

        1. (@fer-no65)

          This perfectly sums up what I said.

        2. If the rubber was gone like you all think, tyres would have hit the cliff first. Not explode all of a sudden. He was on a consistent pace and holding a faster car behind him.

        3. @fer-no65 But 28 laps are just 70% of the indicated 40 laps. Even taking into account weather, track evolution and driving styles, such an error is just… shameful.

          If the tyres didn’t last 40 laps, then Pirelli got it unacceptably wrong with their prediction. If the tyres could indeed last 40 laps, then Hembery is trying to BS us by saying the failure was wear-inflicted.

        4. @fer-no65 I don’t recall Pirelli advising against 27 laps on mediums though…….and if a tyres blows up after that what is the 40-lap indicaton for?

          But actually….yeah, fair enough. I do think that if a recommendation is followed and failure still happens, then if blame rests somewhere it’s on Pirelli, but I guess that’s really a different question altogether.

          1. Tyres should lose performance WAY before they fail. They should only explode in extreme circumstances. Running 27 laps is not an extreme circumstance

            1. 40 laps on tarmac,it doesnt take into account,going off track,over curbs and over bits of gravel.

          2. @davidnotcoulthard we don’t know if Vettel locked up his tyres or maybe he had a differential issue that made the inside tyre wear out too quickly. I mean, there are a lot of factors. I’m not ruling Pirelli out of blame, but I do think that their advice is just a recommendation. It didn’t happen that much appart from that time in 2013.

            1. @fer-no65 If it was simply wearing out too quickly VET would’ve gone over the cliff.

              Or maybe he lockup shortly enough before the failure for us not to notice him hitting the cliff (I highly doubt so though)?

        5. I think Ferrari/Vettel have a point here.

          From my perspective, Pirelli cannot justify this using the rest teams tyre strategy.

          Teams change their tyres based on PERFORMANCE, not DURABILITY.

          The point here is Vettel was having performance enough to fight for a podium but the life of the tyre did not arrive to that point (even having good performance).
          DURABILITY should be safe enough to WARRANT that period of life. If a manufacturer says a distribution chain has to be changed at 90.000 Km they cannot justify a broken chain at 60.000 Km based on that durability is not fixed and could vary according to climate conditions or driving style.

          DURABILITY must discount a % of variability based on those parameters that could affect it, basically because is a SAFETY measure, not a PERFORMANCE measure.

      3. VET has a right ot be angry

        The tires were rated for 40 laps, Vettel only did c.25 laps (adjusted for the VSC) on these tires in clean air so they should easily have held for 26 laps, despite the long stint compared to others.

        He did 17 laps (incl: Qualifying on his Softs) on full tanks, so 26 laps should have been achievable (that is only 65% of their rating), despite elevation changes which stress the rear left more than the right which blew. It was cooler too. The left rear gets much more stress at this track, the tire looked perfectly fine and in OK shape and did not blow.

        They should have lasted, bad luck for VET. They must investigate for Safety

        Of course Pirelli will say it’s nothing to do with the tire, they have to

        1. Vettel clearly would have reached the chequered flag, podium? I don’t know, but Pirelli should launch an investigation because it is a bizarre situation that happened to Sebastian, losing 15 points or 12. You can clearly see for those who watched the interview that Paul was in a bad state and just wanted the interviews to end, I am waiting to see the results of the investigation because that’s the RIGHT REAR and this is a track where the LEFT, both front and rear should get more wear than the rights, unless Vettel was going crazy through the left hand corners.

          1. If the tyres have come to the end, Vettel wouldn’t have been defending against Grosjean. Romain didn’t look like he was gonna get ahead anytime soon. It would have been impossible with a tyre at the end of its life.

      4. Alain Permane (Lotus): “If Pirelli tells us the tyres last 40 laps, they can’t possibly blow up after 28 laps. For us a one-stop strategy was only a backup plan, but we considered it as well.”

        Andy Green (Force India): “If Vettel’s tyres had been worn out, he’d have come into the pits. As soon as the rubber is worn below 30% the lap times go up by two to three seconds and tyre temperatures drop from 140°C to 110°C. You’re driving on ice in that case, you won’t even get anywhere near critical wear. Your team would call you in long before that happens.”

        Maurizio Arrivabene (Ferrari): “A one-stop race was our plan A. We decided that at 11am, using the data the engineers had collected during the practice sessions. There was a Pirelli engineer standing in our garage and he wasn’t just chewing bubblegum. He would have intervened if the data had shown anything suspicious. Our strategy was aggressive, but not risky.”

      5. It’s usually a bit cooler at Spa. There was very little cloud cover until near the end of the race, and with Grosjean pushing Vettel, Vettel was pushing his luck.

        The tire separated in a fairly classic fashion for a worn tire (unlike Rosberg’s blowout which was just nuts).

        1. I think there could be a problem with the integrity of tyres.

      6. 40 laps in Spa is practically the entire race distance. Does that mean everyone could have pitted after 3-4 laps and then switched to medium all the way. This is clearly wrong info from Pirelli.

    2. The wear life is indicated at around 40 laps but it’s an indication

      An indication of what the tyres can do but according to Pirelli what you should not do. Note to self, never listen to a Pirelli engineer again.

      1. At least, not the PR trained ones!

        1. @williamjones Honestly I think we should listen to the PR-trained ones, they’re the ones who probably wouldn’t say what Hembery said. I just can’t help but think Hembery’s not really well-trained in PR :)

      2. Tough luck, but nothing F1 hasn’t seen before. As far as Vettel goes, I know it’s frustrating, but all he has to do is look across the garage at all of Kimi’s misfortunes this season and realize how lucky he has been to have the reliable Ferrari this season.

      3. So worrying…
        So what good an indicator if its useless? How can a team decide their strategy?
        Should all F1 team start hiring mathematician to decipher Hembery’s ‘indicator’?

      4. It’s a complete joke what happened!
        Shame on Pirelli. I hope they don’t try to sweep this under the carpet….

    3. > “The wear life is indicated at around 40 laps but it’s an indication,” said Hembery.

      So, and indication, that I suppose it is conservative means that you can’t do 28 safely?

      1. I remember Sky commentary reported in the race, somewhere close to lap 35, that they would be surprised if he could run more than 25 laps, and they cited the distances run in practice. However, my memory isn’t great, so…

        1. @williamjones
          Yes, but that’s about speed drop-off, not exploding tyres. Vettel’s pace was still good enough to hold Grosjean behind him so obviously hadn’t fallen off the cliff.

      2. A regular lap is 4 to 5 kilometers long. In this case it’s 7 kilometers. So 28 “Spa laps” is about the same distance as a maximum of 40 laps on other tracks.


        I also don’t think that estimate keeps in mind that the Vettel went off track in at least one and often two corners every lap again.

        1. @patrickl

          Wear life refers to the track they’re at. What good would that number do when every track is different….

          Some people here….

          Next we’ll be hearing that a 2 stop strategy is based on a low deg track such as Monaco and shouldn’t be considered when Pirelli say that for a high deg track….

          1. Exactly, that number of 40 laps is a meaningless number. As they say: “Just an indication”. Who says it’s a specific indication for this track anyway?

            Just like there is a 2 second offset between the compounds. That doesn’t mean they have to go exactly 2 seconds faster on the soft compound. Could be 3 seconds depending on circumstances or 1.5 or anything really.

            Besides, Vettel was driving the tyres very hard. All that ramming over the kerbs would obviously limit the structural life of the tyres. It won’t decrease the grip perhaps, but obviously it did delaminate the tyre.

    4. So what he’s saying then is that at the end of tyre life the performance drop off is so small that you can hold off a quick car behind and not even really notice but it’ll be enough for the tyre to blow up?

      Seems, erm, what’s the word? Dangerous, that’s the one.

      1. +1 It’s really silly. Tyres apparently haven’t hit the cliff. How was he holding Grosjean behind him?

      2. Nailed it. If run beyond it’s stated number of laps the tire should lose grip and become useless for racing, it shouldn’t blow up.

      3. In effect he’s saying there are different types of wear. You wear away the tread surface which gets you to the “cliff”. In this case the tyre was abused too much and was internally ripped apart by all the high speed kerb banging.

    5. It was a nonsense reply from a man that has fronted a manufacturer that far too often have failed to deliver on the fundamental requirements of their brief. They need to have a serious review.

      1. @vettel1 There were many things Pirelli should’ve and didn’t deliver, but fundamental requirements of their brief (most of which ridiculous but that’s one of the things that aren’t Pirelli’s fault) isn’t one of them.

        Tyres safely going over the cliff in the particular case of VET at spa, on the other hand…..

        1. This is certainly not the first time a tyre has inexplicably failed. They also seem particularly susceptible to punctures.

          1. @vettel1 The first in a rather decent amount of time since the last inexplicable fanfare-causing failure though……

            Ahem, at least we agree that the tyres VET were on should’ve been safer than it was….

            1. OmarR-Pepper - Vettel 41 wins!!! For Jules (@)
              23rd August 2015, 16:58

              @davidnotcoulthard the second in the same weekend. So fast you forgot about Rosberg? And the real problem is, as Sebastian said, that the tyre should lose grip, not blow out in pieces that could endanger other drivers as well. Both Nico and Seb were lucky they didn’t have their tyres explode at Eau Rouge.

            2. @omarr-pepper
              Rosberg was very lucky his RR didn’t explode in the middle of blanchimont, that would have shot him into the barrier at about 100mph

            3. @omarr-pepper I guess…..but in temrs of weekends I still think quite some time if I remember correctly.

          2. @vettel1

            “This is certainly not the first time a tyre has inexplicably failed.”

            but it does seem like the first time that the tire guy basically, “what do expect”….

            I imagine folks don’t think a tire should explode when it wears out lol.

            1. @uan There seems to be a lot of confusion over compound wear and structural degradation. The latter should not have been affected by the former.

              Indeed also one must consider that the degradation was relatively minor, with less than a second of drop-off. There have been many more extreme cases of wear in the past that haven’t resulted in an explosive failure.

    6. How is it due to Ferrari strategy when they didn’t exceed any limits and tyres haven’t even hit the cliff!!! How was he defending against Grosjean with tyres at the end of their life? He must be superhuman.

    7. so when you do that, any tyre in the world when it gets to the end of its wear life you’re going to have a problem

      Oh please, tell me I haven’t read that… Call me the crazy one, but I’d think the first safety requirement of a performance tyre is that it should never explode purely from wear. We have seen Hamilton wearing a tyre to the canvas, Raikkonen flat-spotting a tyre so hard that the suspension gave up before the tyre did, we’ve seen Vettel doing 60 laps on Pirelli’s very own super softs (that were much softer back then).

      It’s pathetic to shift the blame on Ferrari for Pirelli’s poor tyre construction. And no, stating that “Pirelli has only done what the FIA has asked them to” doesn’t cut it either.

      1. There are two distinct issues here – one issue is that two tyres have failed in a very unsafe manner. The second issue is that wear on Vettels tyres cost him the podium. It’s going to be helful, I think to discuss these things as two seperate issues and not blur the boundaries between them

        1. @williamjones I agree, but I don’t actually think it was wear that cost Vettel the podium. His tyres were definitely good enough in terms of grip to hold Grosjean behind, even with DRS and the Mercedes advantage. To be honest I feel like the rate at which the Pirelli’s wear is better than it used to be in 2011 and 2012, but something much be done so these tyres don’t explode. You can calculate the stresses applies to the tyres on any corner and build a tyre structure that will withstand these stresses in any circumstance while keeping the compounds as they are. That’s an engineering problem for Pirelli to solve.

          1. Oh yes, I agree with you too, I was directing the reply towards Pirelli who seem to be detirmined to deflect criticism of their tyres construction towards Ferrari’s strategy.

      2. There is a word for that: ‘irresponsible’.

    8. he said. “This was pure wear.”

      Yep, Pirelli has done a full analysis on this.

      1. Yep, obviously they had a good look at the tyre and came to the only right conclusion.

        Kinda like Blatter investigating allegations of fixed matches in the champions league and concluding that not to be the case…

    9. I don’t get all the fuss. It was clear to everyone watching that Ferrari were pushing their luck with the tyre stint. When the tyre blew I was entirely unsurprised. This is nothing like the Rosberg incident nor the 2014 spate of blow ups. Ferrari tried to go to the limit and unfortunately went a bit too far. Their strategy was a gamble and it didn’t pay off. Lotus (and everyone else) took a different direction and fully deserved the podium spot.

      I’ve never heard of a racing tyre which could run forever without wearing through, and with Spa speeds the failure is always going to be spectacular. As always Pirelli are the easy target.

      1. @jerseyf1

        It was clear to everyone watching that Ferrari were pushing their luck with the tyre stint.

        Why it was clear?

      2. But the point is the first reaction of a tyre passing the limit should not be complete failure, it should be a huge drop in performance. Vettel was still driving along very well, he wasn’t losing 3+ seconds a lap as we’ve seen in the past when tyres are beyond the limit. That should happen first, not total failure.

      3. Yeah, a team who wants to do 30 lap stint after the manufacturer telling them the tyres have a life expectancy of 40 laps. Crazy to think it would work.

      4. They didn’t try to go to the limit – the indicated limit was 40 laps, they tried to go <75% of that.

      5. @jerseyf1 Clear? As clear as members of the Windsor House being reptiles, maybe.

      6. There is a difference between tyre life (how many laps a tyre can do safely) and how many laps a tyre can do at a competitive pace (strategy/stint length). Ferrari may have been gambling on strategy (performance) but I see no evidence that they were gambling on tyre life (safety).

      7. @jerseyf1

        It was clear to everyone watching that Ferrari were pushing their luck with the tyre stint.

        Excessive wear should NOT cause a tyre explosion. This didn’t happen with Bridgestone. Hamilton was some 5 seconds off the pace at China 2007, his tyres didn’t explode. Same goes with Schumacher towards the end of Hungary 2006. They were on tyres far more worn than Vettel’s tyres today, and they didn’t explode. I never recall a Bridgestone tyre exploding purely because of wear. Pirelli is just pathetic all around.

    10. Steph (@stephanief1990)
      23rd August 2015, 16:08

      If 40 laps was what Pirelli told the teams the tyres could do safely within a race then Ferrari has every right to complain. Twelve laps is a huge difference so Pirelli do have a lot of questions to face.

    11. Hopefully this makes Bernie see that Pirelli is not the choice to go for the future of F1.

      As many already pointed out, the statement that the life was on the end of it’s life is pure bs, if it was Vettel would have not been able to keep Grosjean behind without too much effort.

      And even if it was, IT MOST NOT EXPLODE.

      1. If it were HAM, his soc-med account would probably be full of this, and then it may get on TV, and Bernie may then consider Michelin…..or briefing Pirelli to make decent tyres.

        1. So… Vettel should tweet more pictures of his holidays?

          1. @williamjones No but these things should’ve happened to HAM not VET (would’ve spiced up the chamionship too).

            OK, maybe that attempt at a joke was a tad inappropriate…..

            1. Oh, it’s OK, I was joking too!

          2. @williamjones Preferably with Rihanna.

            1. +1 I thought about posting the same thing, but someone would take it serious and try to argue with me.

            2. @xtwl No, with Sutil and his once-brought-to-races girlfriend.

    12. The wear life is indicated at around 40 laps but it’s an indication


    13. I don’t think anything needs to be said about the 40/28 lunacy.

      F1 desperately needs Michelin.

      1. @lopek I’m not sure whether you are advocating having more tyre blow outs to spice up the excitement or if you think that somehow Michelin is a better tyre supplier. I assume you do remember why Michelin were forced our of Formula 1 last time they were in it?

        1. @jerseyf1

          When Michelin make a mistake they at least own up to it. Could you imagine Michelin coming out and saying “Nope, just tyre wear” after Ralph hit the wall two years in a row.

    14. The wear life is indicated at around 40 laps but it’s an indication,” said Hembery.

      Which doesn’t mean it should be OK for a tyre to explode after 28.

    15. im never ever buying pirelli tyres for car or bike if explosions are an acceptable thing. In the name of driver and racing safety we should start a campaign to boycott pirelli products. Simply ridiculous

      1. I definitely agree with you. I am not a “boycott” person normally, but in this case I’ll never ever pay for Pirelli tyres for the rest of my life. And I’ll make sure no one I know pays money to buy those either.

        1. Send that info to Pirelli. That might put the pressure on and make them pull their valves up a bit.

    16. For me the tyre failure was completely unacceptable.

      Its fine to say that Ferrari pushed them too far by trying 1-stop but even if that is the case it should not suddenly fail like it did, Lose a lot of performance yes but not a sudden failure.

      Look at Kimi at China in 2011 for example, He tried 1-stop less than everyone else but rather than suddenly fail he simply lost 4-5+ seconds a lap & was forced to pit. That is what should happen, A complete failure after 28 laps when you were told they could last 40 is simply unacceptable.

      To be honest a lot of the failures that Pirelli have blamed on teams pushing limits the past few years (Tyre swapping, cambers, pressures, using kerbs) is all stuff that teams have done for decades on dozens of other tyres & all stuff that tyres should be able to withstand & stuff that teams/drivers woudl expect the tyres to withstand. You can argue the rights/wrongs of some of them but tyres should still have enough of a safety margin built in that you woudl never expect doing these things to cause a total failure.

      1. I agree, the tyres need to be more robust and should be able to stand some level of abuse, which is a separate issue from performance.

    17. how did vettell finish 12th in front of 4 cars surely he should have had a D.N.F. after a puncture 2 laps before the finish

      1. You don’t have to be running at the finish to be classified, you just need to have completed at least 90% of the race distance. Vettel had, and he’d covered more laps in less time than those behind him.

    18. There are a few things that are bothering me:
      1. If Pirelli is saying the wear life of the tire is about 40 laps, shouldn’t that be a conservative indication? The discrepancy between 28 and 40 laps is quite huge (84km around Spa).
      2. Yes, Ferrari were pushing the limit of the tyre, but if that tyre really was at the end of its wear life, should the tyre not indicate that to the team/driver in terms of lap time? It didn’t seem to me that Vettel was hitting the cliff or was even beyond it. He wasn’t several seconds slower than Grosjean. Instead of just giving up the tyre should drop of massively in lap time like we have seen before in other races.

      1. So the logical answer to both questions is the tyre wasn’t at the end of their life-span.

        1. Or it was and Pirelli mislead everyone in the weekend that the life-span is 40 laps while I reality was about 25.

          1. Or Pirelli’s tires indicate the end of their wear life by catastrophically failing.

            Neither of those conclusions put a very good light on Pirelli.

      2. The difference between 40 laps at Spa and 40 laps at Monaco is huge too.

        1. That 40 lap indication is specifically for the medium tyre at Spa.

    19. There are a few things that are bothering me:
      1. If Pirelli is saying the wear life of the tire is about 40 laps, shouldn’t that be a conservative indication?

      Haven’t thought of that, but that’s a great point. Engineers aren’t supposed to make extreme, borderline estimates, but conservative ones, usually with safety factors and such.

      1. Yeah. It makes it all the more unacceptable!

    20. Vettel’s lap times over the final stint-

      2:22.634 – VSC
      2:04.049 – VSC

      1. A bit of drop off but nothing that would indicate the tyre was at the end of its life & certanly nothing that would have me worried if I was the team or driver.

        1. Yeah and he was defending at the end, they generally get a bit slower defending. There is nothing there indicating “cliff”. How is the end came before hitting the cliff???

      2. Exactly. For comparison here are Perez & Massa’s times for laps 35-41, they both stopped for their medium tyres during the VSC. (Lap 41 is the last lap of Vettel’s listed above)



        It is quite clear that there was no problem with Vettel’s pace.

      3. @gt-racer That is indeed a good indication. I was there and had a good view on Eau Rouge and the Raidillon.
        Grosjean was having a hard time when he rejoined Vettel. For three or four laps he stayed behind, visibly too far in the Raidillon to be able to overtake on the Kemmel straight, and he even dropped a bit. At that time, I was convinced he wouldn’t be able to overtake him, I was a bit disappointed.

        Just to say that the only real problem indeed is that instead of exploding the tyres of Vettel should have dropped in performance to the point that he would have been forced to change it, and we clearly don’t see that in the data.

    21. It was probably just bad luck.

    22. These are Vettel’s last 6 laps (before the tyre blowout):


      There is no obvious degradation, let alone “falling off the cliff”. If he’d been losing 3-4 seconds a lap before the failure, you would have pinned the blame on Ferrari.

      1. Yeah, I watched the gap times and at first Grojean was catching up, then that Seb was keeping the gap. I thought he’s managing things, keep going… (I’m a fan of Seb’s) then bang.

        He’s dead right – unacceptable. Tyres should lose grip when they fail, not explode, leaving it to lady luck whether the driver is flung into the tyres at 200mph.

      2. +1

        Tyres were not EOL. They weren’t even worn out yet. Not even close. Everybody knows if that tyre hadn’t gone bang Vettel would have finished third. Hell, he was pulling away from Grosjean up to Eau Rouge.

    23. So Pirelli tyre tolerance level is 30%, this is what he is saying basically. So let’s see, my car (a performance family sedan) takes tyres with a Y speed rating. That 186 mph max speed allowed. 30% below that is 130 mps, which is a speed my car can easily achieve (max is 155 mph). Therefore, if Pirelli accepts a tolerance level of 30% within their calculations, that means my car is actually not safe wearing Pirelli tyres. I think every consumer should weigh this in very carefully when buying tyres for their car. In my case, that’s around £150 per tyre. No, Pirelli will definitely not be getting my money anytime soon, that’s for sure.

    24. Was just told that there were a few tyres on GP2/GP3 cars this weekend that showed signs of failure similar to what happened to Rosberg on Friday.

    25. So am I understanding Pirelli here…We will give all the teams an indication of how long the tyres will last but this is not an exact number, just an indication. HOWEVER, if you go over the life of a tyre by a lap, it will explode because that’s what all tyres do when they exceed their life.

      Problem with this simply ridiculous logic from Paul Hembrey and Pirelli is that the teams have no idea the exact tyre life. Also what happen to the tyres dropping off the cliff? Surely Pirelli cannot seriously be saying that it is ok for a tyre to explode because it’s worn…if they are then, in my humble opinion, it’s time for them to leave the sport because it is no exaggeration to say that Vettel could have been killed or seriously hurt had that happened through Eau Rouge

    26. It shouldn’t have happened and it’s no more acceptable than any of the other tyre blowouts we’ve seen down the years, but what can we expect when Pirelli aren’t allowed to test the things properly and have to come up with tyre selections and ‘indications’ (which are only general guides) based on simulations?

      1. It’s the freaking 11th race of the season. If Pirelli thought the tyre was unsafe, they should have updated their compounds by now.

        A tyre exploding due to a lack of testing makes sense in Australia, not when you’re past half season.

    27. Ever notice how it’s NEVER Pirelli’s fault? Not once in the past 5 seasons have they EVER, not even once, accepted responsibility for their awful tyres!!!

      And don’t bother regurgitating the old lie about the teams or the FIA asking them to make tyres that are terrible. It NEVER happened.

    28. VET has a right ot be angry

      The tires were rated for 40 laps, Vettel only did c.25 laps (adjusted for the VSC) on these tires in clean air so they should easily have held for 26 laps, despite the long stint compared to others.

      He did 17 laps (incl: Qualifying on his Softs) on full tanks, so 26 laps should have been achievable (that is only 65% of their rating), despite elevation changes which stress the rear left more than the right which blew. It was cooler too. The left rear gets much more stress at this track, the tire looked perfectly fine and in OK shape and did not blow.

      They should have lasted, bad luck for VET. They must investigate for Safety

      Of course Pirelli will say it’s nothing to do with the tire, they have to

    29. Normally a worn out tire indication is falling lap time and lack of grip, not tyres bursting out of nowhere. Pirelli should accept their fault that they gave wrong information to the teams.

    30. Pirelli’s previous tyres have started to lose grip – ‘fall off a cliff’ – in the past, so one does wonder if the tyre was damaged in some other way. It isn’t acceptable for a tyre to fail in this way without any prior noticeable loss of performance.

      However, the FIA must take some responsibility too. Pirelli have no suitable test program for their tyres (aren’t they still limited to using an old Lotus running the far lower torque V8 engine)? With new consructions for 2015 they’re limited to basically learning as they go along based on the experiences of the teams. There’s been no tracks I far in2015 that stresses the tyres in the same way that running an old tyre flat out through Eau Rouge does.

      I hope there’s no parallel to be drawn with the FIA’s recent decision to further limit pre-season testing. This is not a performance issue, it is safety, and running what are essentially brand new cars each year with thousands of new components is worrying.

      Allow proper testing FIA, and make future accidents as preventable as possible.

    31. This is garbage. All tyres should last 25 laps at Spa before exploding, end of.

      If they don’t, then they need to be redesigned.

    32. Never buying Pirelli tyres. That’s for damn sure.

      A company that deems it acceptable for a tyre to EXPLODE!!!! before the tyre life runs out is unacceptable to me.

      Imaging going down the highway, worn tyres but still above the legal limit. Suddenly BAM….

      Good job Pirelli. Another kill.

    33. How can you blame pirelli? If you want a one stop, you should do the runs in practice. If you don’t, you know it’s going to be a uncertain area and these things can happen. Especially with all the kerbs and the fact that vettel had to push at the end.

      Also, usually teams don’t listen to pirelli. They check their own data from practice and plan accordingly and now you are going to tell me they say:”but pirelli said they were good for 40 laps?” Just bad luck, but it was a gamble to begin with.

      1. It wouldn’t be a good thing for a tyre to explode in practice without warning either.

    34. You just shouldn’t get a blow-out from old tyres, if that happens then something’s wrong. These failures should never occur without external factors. Ferrari’s decision to one-stop was okay until Pirelli had strickly forbidden the teams from doing less than 27 laps and Ferrari’s just ignored it. I doubt it had been the case.

    35. Imagine now, which engineer or team is going to believe Pirelli about the tire’s life span from now on. They all will be defensive when doing the race strategies. I can assure you Pirelli will claim that they will investigate what caused the explosion of the tire and co me up with the lie that it was “debris” that caused it just to evade responsibility. A joke f1 has becoming. Another year of complete domination by Mercedes, there is no way next year will be any different, a new engine provider that can’t make improvements due to the ridiculous regulations and honda has absolutely everything to lose as they don’t seem to be able to reverse their current form any time soon.

    36. I just had an E-mail conversation with an engineer from Lotus who told me that several engineer’s from several teams raised concerns about the tyres yesterday because some images taken through Eau Rouge was showing that the standing waves seen on the sidewall were too extreme & that they had some concerns over structural integrity.

      He also explained that the engineer’s put tyre degredatioin into 2 categories, Red-Deg & Yellow-Deg & they would consider Vettel to be in the Yellow-Deg phase, Performance was just starting to decline but they woudl not consider it reason for a pit stop or consider it to be a failure risk.

      Ended our conversation by saying that there are questions for Pirelli to answer if it does indeed turn out to be a purely wear related failure & that the engineer’s want further clarification on that & the standing waves issue raised yesterday.

      Oh he also confirmed that they were told that the tyres were SAFE for 40 laps as recently as 1 hour pre-race & that Lotus did consider a 1-stop strategy & had it as there plan B.

    37. Very confidence inspiring. 40 laps means 28. Basically Pirelli advice for Monza is the tyres will do more than 1 lap but less than 100, pace can be fine you will only know you should of changed when the tyres explode at 220 MPH good luck.

    38. I don’t usually comment but the reaction to this has prompted me to. Surely it should be obvious that the issue here is safety, not whether a team were taking a risk on strategy. When a team takes such a risk with tyre strategy, what they should be risking is losing performance in comparison to others on more conventional strategies and therefore losing places and points. What they should *not* be risking is the life of the driver. With tyres that fail catastrophically due to wear with hardly any drop off in performance, that’s exactly what is at risk. For Pirelli to suggest that a failure like Vettel had today is simply what they should expect when a tyre reaches its wear limit is unacceptable to put it mildly, imho.

      Or to put it more simply, performance should be the limiting factor with tyre use, not failure-risking wear.

    39. Well it seems everyone agrees. Pirelli should be for the high jump. I really think they should switch to Michelin.

    40. If Pirelli indicated that you could run the medium tyres for around 40 laps and if Pirelli’s engineer at Ferrari did not warn the team when he saw what they were doing with Vettel’s strategy, then Pirelli should hold their hands up and apologise. I believe they have never accepted responsibility for any of their tyre blowouts and it just does not sound credible that someone or something else is always to blame for the failures of your products.

      However, FOM and FIA should also be held responsible as they have been trying to replace healthy competition with gimmicks that are supposed to artificially make races exciting for several years and Pirelli’s “designed-to-degrade” tyres are one of such gimmicks.

    41. Vettel and Ferrari took the risk when no other team took that risk. OK they may have perceived it to be a fairly low risk and yes probably 9 times out of 10 they would be OK but this time they didn’t get away with it. Other teams didn’t take the tyre wear risk and they didn’t have the blow out. Hamilton took that risk once in China and it didn’t pay off for him either. Racing is about taking things to the limit to get the best result. Had Vettel been conservative and pitted twice he would most likely have finished 5th or 6th so he wanted to take the risk. His decision – and he must take the consequences. It’s not realistic to think every tyre made by any tyre company is exactly the same as every other tyre. Each tyre will have tiny imperfections. I’m sure he could try that 10 times and it would work 9 times. today bad luck.

      1. but hembry did not say, random error, we follow six sigma but stuff happens. He said it was your own fault for running 27 laps. “Sorry not sorry”, is not a response that makes sense here. The Hamilton example goes the other way, no? The tire went down to the Kevlar band and it held fast even going down that huge Shanghai straight several times like that. If a team had a reason to fear a tire would explode in that condition at even 200mph we would have looked at that episode much differently at the time and in retrospect.

        1. It’s quite likely that wear was the primary cause but that something would have cut the worn tyre to cause it to explode. A kerb or a piece of debris. When Mansell’s tyre exploded in Adelaide 1985 it was also wear plus debris. If you take the wear to the limit, you’re risking even small debris causing a big issue. Without the extreme wear the debris or kerb would not be an issue.

          1. @gazzap

            What extreme wear?

          2. I’m not a tire engineer but I can’t follow that reasoning. The core of the tire is protected by a Kevlar band and metal structure. The few mm of rubber on the outside would seem to make hardly any difference to the puncture worthyness of the tire. And even if punctured, the nature of the failure should have nothing to do with whether there was 3 or 1 mm of rubber left. That rubber is not holding the tire together and that’s not its purpose. In any case, as has been reported here, the wear was not extreme at the time of the failure, at least in view of lap times.

            1. You don’t need to be a tyre engineer. You see all the time front wing’s clipping rear tyres just slightly and then the whole thing explodes. Put wear on that tyre and the tyre requires less of a trigger to cause it to explode. Once punctured, the tyre normally falls apart pretty quick at those speeds regardless of kevlar.

    42. I feel like I’m taking crazy pills. Under no circumstance should tire wear, by itself, result in catastrophic failure of the tire. For a tire company to come out and say this is nuts. Not a very good recommendation for a set of P Zeros for a road car, is it.

    43. After the tyre blew I was not very happy, a tyre shouldn’t fail like that and I was already a bit annoyed towards Pirelli, because that’s the second time this weekend. But I wanted to wait for their explanation. After what Hembery said I’m even more mad.
      The tyre was at the end of its wear life? Seriously?! After just 28 laps and very minor performance degradation?
      They’re basically saying that it’s normal that tyres explode if you have a slightly longer stint than usual. I’d feel so safe if I was a driver!
      That’s crazy.

    44. Interesting that he blames the failure on pure wear. I can’t remember the last time a tire failed simply because of wear.

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