Stewards take no action on Merc, Wolff calls for clarity

No further action was taken by Italian Grand Prix race stewards following an investigation as to why Lewis Hamilton’s left-rear tire was under the allotted tire pressure limit set by Pirelli. Teammate Nico Rosberg’s left-rear was also under inflated as well.

Conspiracies flew as the allegations that the left rear tire was an unfair advantage and that Mercedes knowingly filled the tires to meet scrutinizing only to lower when the tire cooled off. The FIA race stewards were convinced the team followed proper procedures and assessed no penalties leaving hamilton’s victory untarnished by a penalty or worse.

Mercedes boss Toto Wolff, ever quick with an opinion, was not about to be silent on this issues telling AUTOSPORT and press:

“The question is about the procedure,” said Wolff. “We check them when we put them on the car.

“You could say when is the moment you should actually check them – five minutes, eight minutes before?

“It is about defining the procedure on when the tyres are checked in the future so it’s the same for everybody.”

So did Mercedes deliberately try to set pressures at one level and then allow them to drop thus fooling the FIA scrutineering process? Wolff says rubbish:

“I can absolutely rule that out,” he said.

“We have worked the whole week after Spa with Pirelli in order to make the tyres safe.

“We are very much part of trying to guide them on minimum tyre pressures and minimum camber, which we already had on our cars in Spa.

“So I can rule out that we would try to gain an advantage in a way that is unscientific and uncontrollable.

“How do you measure how much a tyre pressure drops when you disconnect it – and why would you only have it on one tyre and with discrepancies on two cars?”

So now we need new rules and regulations and procedures that F1 fans at home can’t follow or understand and teams must account for. It’s becoming like the US government who seem to think that life is about creating new laws and regulations daily and burdening the system with so much red tape that its efficacy is reduced to the ability to confuse itself and the people it governs.

Just how many race infractions, regulatory infractions, technical infractions and actual driver and team infractions are the stewards now responsible for during a race weekend? It’s impossible to manage and it’s getting out of hand to be honest. the 160+ penalty positions handed out this weekend between Red Bull and Toro Rosso are just sheer knuckle headed madness.

As for the tires, Lewis Hamilton foreshadowed this issue by saying:

“In terms of putting the pressures up, I don’t think it’s the right thing, but they might not do it anyway.

“But I don’t think any of us have tried 5psi more because they are not designed to have 5psi more; they work in a range. So we will be moving out of the optimum range of the tyre, we’ll be using a different part of the tyre, which means more wear, less grip. It’s going to be a disaster.

“ So I hope they don’t put 5pis more in. A couple is ok.”

He’s right, they didn’t do it in his case and it nearly was a disaster for him. On one side of the equation, this is a bit baffling but as much invective that was heaped on Pirelli’s demand for 5psi more air pressure in the tires for Monza, you can also understand how just a little less air is also a big impact on the car. You can read our own Paul Charsley’s take on how it impacts a car here.

So if adding a little air is a bad thing and the drivers, like Lewis, were seriously not happy about it, then running a lower pressure would have another impact logically. While I think a lot is being made of this and it’s a bit of a storm in a tea cup, I do not want to marginalize the effect of running lower tire pressures either.


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“So did Mercedes deliberately try to set pressures at one level and then allow them to drop thus fooling the FIA scrutineering process? Wolff says rubbish”

Do you really believe that he is going to say “yes, we did it on purpose”? Come on, they got caught and got away with it.


Tom Brady was spotted hanging around the Mercedes garage, and seen to be texting Niki lauda. Allegedly

Paul KieferJr

NASCAR faced similar issues regarding tire pressue. They created a rule or two to address this issue. Is it a performance issue? Yes, absolutely, and that was proven out. However, for obvious reasons, it’s also a safety issue. You certainly don’t want to run a pressure that’s too low and thus create more wear on the outside (and, of course, too high creates more wear in the middle). While we in the ordinary life don’t have such a law, we do have safety inspections, and tire wear is a part of those inspections, and the tire manufacturers themselves recommend a… Read more »


I look forward to hearing what Charsley has to say, but I am pretty sure that 0.3psi on one tire will make no difference, and this ‘controversy’ is a nonsense.
The important thing is that LH comprehensively destroyed the field this weekend, taking a big step towards his 3rd title

Tim C.

If there were rules in place regarding tire pressures (minimum or maximum) then penalize them and be done with it. But, I in no way believe it contributed to Lewis’ win. He just had an absolutely dominant car all weekend. You have to hand it to the Merc team, they did their homework and built a fantastic car and power unit package. Now, regarding the penalty madness, enough already. Handing out 160+ penalty positions between two teams is just ridiculous. It’s now to the point of being comical. Something has got to be done . . . and soon. If… Read more »

Paul KieferJr

USA here. In theory, a rule should be reasonable. The punishment must fit the crime, and it has to be reasonable enough that everyone can obey it without going to extroadinary lengths to do so (“onerous”). Asking teams to make it through the season with only four, five, or even eight engines is not “reasonable”. Engines are designed only with a limited amount of durability. You can have speed or endurance, but not both. Something has to give.


In the V8 era they introduced the limit on engine count, they brought it down every year or two. The limit hasn’t been that imposing until this year when teams have blown through their allocations very early. Last years Renault seemed to last much longer, but probably wasn’t being pushed as hard. Having the engine count limit and a few other changes, like the extension of the points giving places has led to much more predictable racing. For teams it is no longer an all or nothing prospect and so they have focused on reliability more. The extended parc ferme… Read more »


It isn’t worth making an issue out of the new rule and following it at home. Can you tell me the maximum length from the reference plane for the car? Actually can you tell me where the reference plane is? I wouldn’t expect most fans to know or care but a bunch of things like this get checked at scrutineering. Adding a new item to get checked on all the cars over the weekend and a set after the race won’t make a lot of difference to the viewer, it is just news while the tyre issue is so hot… Read more »


If the intent of the rule is to ensure a minimum safe pressure under race conditions, then rather than measure pressures on the line before the formation lap, they could set and check pressures when the types have come up to temperature under the blankets. An anti-tamper seal could then be applied to the fill point and checked when the tyres come off the car after each pit-stop. This could be delegated to the Pirelli tech assigned to each team if the FIA reckon they don’t have the people.


Certainly, the difference in temp and pressure is relatively predictable, even taking into account the rubber deforming (i.e. not following ideal gas laws). Something that they certainly can account for. My earlier guess, seems to be a bit off about the situation and when the measurements were taken. Merc were pretty close to the minimum (19.3 vs 19.5 I read somewhere), a bit like the fuel flow issues with RBR last year. I would be interested to see the actual minimum and tolerance allowed (plus what they are using to measure these as most inflation gauges are pretty imprecise)


The relationship between pressure and temperature is predictable, however I don’t think the temperature would have been the way it is reported they took the measurements (some unknown time after tyre warmers were unplugged). The rate of temperature drop will depend on warmers, how long they have been removed, ambient temperature and wind. There are just too many variables.

Good gauges will measure to 0.1Psi accuracy. The FIA would have to be using a gauge with current certificate of calibration or else their measurements would be challenged.


All the teams have IR lasers pointed at the tyres for temp sensing (and inferring pressure from that) as the cars race. The sensors probably aren’t certified to be precise enough for use for scrutineering and will give surface temps but if they are going to go whole hog on the thing they could probably sort that out.

Paul KieferJr

PV = nRT

charlie white

2 drivers were disqualified from the GP2 race for the exact same infraction as Mercedes-Benz/AMG. What kind of example does this set for future drivers and teams rising to F1? On Twitter, there was a long and active thread with F1B regular FakeCharlieWhiting and others on whether if this were a technical regulation violation or race infraction. I believe that’s what Rob Smedley and Pat Symonds were arguing on the former which would lead to disqualification. Regardless, Lewis Hamilton and team got a “get out of jail free” pass from Charlie Whiting and FIA.

Graeme Fuller

The only similarity I can think of is when WRC banned the use of foam in the tyres. This meant the tyres instead of being softer and when punctured, filling with foam, had to be harder to survive the conditions. Initially in the following year some teams had suspension parts being punted through the bonnet. Eventually adjustments were made. Curious as whether this is a case of a F1 team nudging the grey area/rule interpretation or something else. I cannot say as I have no F1 experience. If it was an experiment Louis could have lost 25 points, with no… Read more »

Andreas Möller

It’s easy to see this as spawning yet more regulations that nobody can follow or remember. But another way to see it is that it is the method of measuring that needs to amended. Pirelli/FIA had set a minimum tyre pressure, and a maximum tyre temp (to stop teams overheating the tyres to “prop up” the pressure at the time of measuring). That didn’t account for what would happen if the temp was too low when the pressure is tested, as was the case here (in Rosberg’s case, to the point that his left rear tyre was 1.1psi below the… Read more »

Paul KieferJr

Here’s a thought: Most passenger cars these days have pressure sensors in the tires to monitor these things. Why not just stick them in the wheels of a Formula 1 car and monitor them real-time? Varying temperature issues can be solved using the Ideal Gas Law (Pressure times volume equals a constant times a mole constant times temperature, or “PV = nRT”).