F1's engine war comes alive at Monza

Engines were always going to be the dominant factor in deciding who would do well in the Italian Grand Prix, even though much of the talk in the build-up to the weekend (and after Lewis Hamilton claimed his seventh victory of the season) was of tyres and how they should be pressured.

We all know Formula 1 is an engine game right now. A game Mercedes is clearly winning. But perhaps not as easily as it once was. Conventional wisdom would suggest Monza's long straights and relative lack of turns compared to other circuits on the calendar would only strengthen Mercedes' hand, and further expose the difficulty Ferrari, Renault and Honda (particularly the last two) still face in trying to make a real race of the world championship.

At first glance, Lewis Hamilton's 25.042-second victory over Sebastian Vettel doesn't suggest Mercedes will have much to worry about any time soon, but the catastrophic fate of his team-mate Nico Rosberg could, perhaps, be a small signal that Mercedes is facing greater pressure from behind than at any other point since F1 adopted V6 hybrid engine technology.

Hamilton took a dominant victory in Ferrari's back yard © XPB

Mercedes spent all of its remaining seven 2015 engine development tokens to introduce what team boss Toto Wolff described as the "phase four" power unit to its two cars for Monza. The team's engine chief Andy Cowell admitted this represented a risk, because really it came one race ahead of the planned schedule.

Tempted by the fact this circuit would reward pure engine performance like no other on the calendar, Mercedes decided to take the plunge. Doing so meant more power, better efficiency, and an opportunity to start gathering valuable data on what Wolff called a "different development direction" to previous power units, which had been in operation since the Canadian GP in June.

Not to be outdone at its home grand prix, in front of the loyal and passionate Tifosi, Ferrari spent three of its remaining seven development tokens in order to bring its own new specification of engine to this race. After all, Ferrari knew it needed to be as powerful as possible at Monza, following the embarrassment of 2014, where Fernando Alonso retired with engine problems while Kimi Raikkonen finished a lowly ninth - over a minute behind Hamilton's winning Mercedes.

The Scuderia's technical director, James Allison, described Ferrari's latest power unit as "a useful step forward", and the fact that Vettel was able to slash last year's finishing time deficit to Hamilton by 40 per cent compared with Raikkonen's effort last year gives some indication of the progress Ferrari has made over the past 12 months.

After qualifying, where both Ferraris lapped within 0.3s of Hamilton's pole time, the Tifosi was dreaming of the possibility the Scuderia might topple Mercedes on home turf. That was never realistically likely to happen. Hamilton's healthy upgraded Mercedes was still a clear step ahead of anything Ferrari could put together this weekend.

But the fact Rosberg was only able to qualify fourth, just about matching the pace of the two red cars, offers the first clue that Ferrari may be putting Mercedes under more pressure than ever before, essentially 'forcing' its rival into taking risks in pursuit of performance for the first time since these rules were adopted.

Rosberg had to wait until the pitstops to clear the Williams drivers © XPB

Rosberg had to revert to the previous specification of engine for qualifying, after a "chassis issue" caused a "strange oscillation" in the new one during final free practice. This was eventually traced to a water leak that 'contaminated' the unit. That meant Rosberg was back to running the engine he used to finish a close second to Hamilton in the previous race at Spa.

It took Rosberg most of the first half of the Italian GP to recover from a slow start, caused by Raikkonen's second-placed Ferrari failing to get away from the grid directly in front of his Mercedes. Rosberg had to repass the Force India of Sergio Perez early on, and make use of an early pitstop to leapfrog Williams pair Valtteri Bottas and Felipe Massa.

Once into clean air on a fresh set of medium tyres, Rosberg attempted to hunt down Vettel for second place. Ultimately, Rosberg's smoky retirement on lap 51 of 53 was a result of pushing his worn engine a little too hard in this vain pursuit.

If you analyse the pace of the top three runners from lap 27 (the first proper flying lap after Vettel's sole stop on lap 25) until Rosberg's engine went bang, you can clearly see the Ferrari holding its own against the older-spec Mercedes.

Rosberg averaged 1m27.629s over 24 laps, while Vettel lapped in 1m27.726s over the same duration. That represents a deficit of just 0.097s per lap for the latest specification of Ferrari compared to the previous specification of Mercedes. Of course this is a vague comparison that doesn't allow for chassis and driver discrepancies or dealing with lapped cars (and admittedly Rosberg's engine was clearly tired), but it is instructive because both drivers were pushing very hard to out-do each other.

Hamilton's pace was 0.293s faster than Vettel's Ferrari over that same period, during which he was instructed to go for "hammer time" laps by his team, in order to protect against a fear he might receive a penalty after the race for starting with a rear left tyre pressure measured 0.3psi below the minimum limit set by supplier Pirelli before the weekend.

Hamilton was untouchable thanks to a phenomenal opening stint © XPB

So after all this, despite a 25s defeat in front of its home crowd, perhaps Ferrari - which has four development tokens remaining to use before the end of this season - is in fact only one major development step away from catching Mercedes in F1's power game?

"I always said our development, in terms of the car and engine token, would be gradual," said Ferrari team principal Maurizio Arrivabene. "We spent a couple of tokens here; we were satisfied by the performance of the engine.

"Now it is a kind of tactical decision on what we want to do with the rest of our tokens. We are still in development with this car, we don't give up, and we will continue until the end of the season."

Although Rosberg paid the price for Mercedes' decision to upgrade its engines a race early, the eventual result of which he described as a "disaster" for his championship hopes after slipping 53 points behind Hamilton, Wolff defended the decision to bring the new power units to Italy.

"We brought that phase four engine because we wanted to understand if that direction of development was the right one," said Wolff when asked whether the decision reflected the fresh pressure Ferrari is subjecting Mercedes to this season. "It was a bit of a risky call and we saw what happened to Nico.

"In hindsight, yes we lost a car and Nico lost valuable points, but this is a competitive championship. And it's going to be one next year, so the earlier you can understand which direction you need to go development-wise, the better it is."

Mercedes will now investigate whether Rosberg's intended new-spec engine can be recovered and used for the next race in Singapore. The good news is Mercedes can still reflect on a crushing victory for its other car over the best of the Ferraris.

Hamilton did the damage over that first stint on used soft tyres. He averaged 1m28.177s over the 23 flying laps before Vettel's pitstop. Vettel was a massive 0.644s per lap slower on average than Hamilton during that period.

"I thought we were similar in laptime for one or two laps and I thought maybe we'd get a chance to close the gap," said Vettel. "But then... in football you call it the 'second lung'. It's a German saying that makes no sense in English. He just found a switch and pulled away."

Wolff explained Mercedes' position to the media on Sunday night © LAT

That suggests Ferrari still has some way to go to match Mercedes, but was that simply because Hamilton's car/engine combination was so much better than Vettel's in the race? Or did the tyre pressure controversy that led to a tense finish play some part in Hamilton's prodigious first stint?

The FIA eventually decided it was satisfied Mercedes set the pressures correctly when the tyres were fitted to the car, and that it followed the correct procedures, despite finding the rear-lefts on both Hamilton's and Rosberg's (the latter by 1.1psi) cars below Pirelli's minimum limit, which is enforced for safety reasons.

There will be moves now to improve the systems by which these pressures are measured, suggesting there is possibly some anomaly with the checks performed at Monza. But nevertheless, the question is whether Mercedes gained an advantage from these tyre pressures being found slightly outside the minimum, and whether Hamilton should have been disqualified from victory for not being in compliance with this limit before the start of the race.

Williams performance chief Rob Smedley was fairly emphatic: "The intention of running lower tyre pressures is for performance," he explained. "There is a document that Pirelli sends at the start of the weekend, and that document stipulates what the pressures have to be out of the blankets.

"Effectively that's a technical infringement and an infringement on safety. We have a process in place to not let the tyres go below minimum pressures when they come out of blankets.

"It doesn't matter what it is. If it's 0.3 or 1.1 or 10. When you have a technical regulation, you have to stick to that regulation. The wings we measure, and get to within half a millimetre within the regulations. We don't go outside of the technical regulations. If we did go outside, and we were caught, we would be disqualified."

The tyre pressure limit is set for safety reasons, rather than competitive ones, though it's unhelpful in this case that the two are interlinked. Nobody wants tyres to fail, for obvious reasons - especially given what happened at Spa last time out, but it's also true that lower starting tyre pressures should give you more grip and help reduce overheating during a stint.

"They definitely had an impact on performance in race running," said Smedley of Pirelli's Monza limitations, which required an increase of 1psi front and rear compared to Spa. "They give you a stipulation of where you have to start and then the car energy will take you to a certain pressure.

Smedley's position on the tyre pressure debate was clear © XPB

"Where do you want to go with it? There's a technical regulation, and that technical regulation is in place in order that you don't infringe it. Where do you want to go with wings, with car heights? What do you do with your power units?

"It's a technical regulation and we've all got to abide by it. If we all went a little bit outside [in various areas], all our cars would be two seconds quicker. So we don't take a little bit anywhere. There's a technical regulation and they've infringed the technical regulation. End of story."

Except it wasn't the end of the story, because the stewards deemed Mercedes didn't break any rules. From this we can only conclude there was possibly some error in the readings taken that caused this whole storm in the first place, or an error in the procedure for taking those readings that meant the stewards couldn't reasonably take action.

Mercedes insisted it had followed the proper guidelines in conjunction with its Pirelli engineers, and that the "tiny discrepancy" must have been down to the tyres cooling off between the time they were fitted to the cars and the moment the two Mercedes and the two Ferraris were checked on the grid.

Wolff suggested the procedure for checking the tyres needed to be cleared up in the future. "It is about defining the procedure on when the tyres are checked so it's the same for everybody," he said, adding that his team was not informed of the discrepancy in time to raise pressures before the start, and he insisted Mercedes had not deliberately set the tyres in such a way as to ensure they dropped below the minimum limit after checks were performed.

"I can rule out that we would try to gain an advantage in a way that is unscientific and uncontrollable," he said. "We don't know why we had such a discrepancy. At the end of the day it can be performance costly if you have one tyre with a different pressure to the others."

It's not really clear whether Mercedes made a misjudgment (or a clever calculation), whether Pirelli and the FIA failed to take the correct measurements at the correct time (or something went awry with that process), or whether Mercedes really gained anything from whatever anomaly might or might not have been discovered.

In the end it didn't matter. Hamilton kept his win, and Ferrari must still work out how to bridge the last bit of that gap to get on terms with Mercedes. If it can do that over the remaining seven races and the winter of 2015, then next year's Italian GP could really be something special for the home crowd.

But Mercedes will be working hard to ensure one of its cars remains the dominant force, whatever tyre pressures it ends up running.