The FIA is still considering how to respond to the accusations leveled at Mercedes during the Monaco Grand Prix that they broke the F1 rules by conducting a test ahead of the Monaco Grand Prix.

On Friday the sport’s governing body announced it was also questioning Ferrari about a test it performed ahead of the Spanish Grand Prix. Ferrari’s test was conducted using their 2011 car, while Mercedes used their current chassis.

Pirelli have denied Mercedes gained a benefit from the test, which was conducted to assess potential changes to the tyres.

But one former F1 mechanic believes Mercedes could have gained a “huge advantage” from the test. Marc Priestley spent ten years as a McLaren mechanic and has extensive experience of how testing is conducted.

The details of what Mercedes ran on their car during the test are unknown. Priestley pointed out that as the FIA were unaware of the test, they were not on hand to monitor what Mercedes were doing:

“When you go to an aero day, for example, quite often you’ll get an FIA representative there, they’ll send somebody along. You have to inform them the test is happening. Quite often they’ll send somebody along just to make sure things are in order and you’re not doing something you shouldn’t be, more mileage than you should be, things like that.”

That meant there was nothing to stop Mercedes from testing whatever they like: “From that point of view they’ve got an open book to put on whatever sensors, whatever testing and development equipment they want on it.”

‘Every department will want something on the car’

Whenever an F1 team schedules a test those within the team are always eager to take advantage of the opportunity: “Whether it’s an aero test [in a straight line] or a full track test somewhere, the entire factory will come out of the woodwork and want something bolting onto the car,” Priestley explained.

“Whether it’s sensors somewhere, new parts, something experimental, every department will want to have something strapped to that car. It’s a very rare opportunity, particularly in this day and age where track testing is so limited. It’s a massive chance for them to try all sorts of things.”

“They’ll have almost certainly had various aero sensors on the car, for sure, because that’s something they can be monitoring while the car’s pounding round all day long. So the aero department will have been heavily involved.”

The value of mileage

Mercedes also had the chance put mileage on new components and potentially bring forward the point at which they could be used on their race car: “When you have new parts coming to a Grand Prix we had a sign-off mileage that they wouldn’t be allowed to run the part on a race car until it had been signed off on a test car and done a certain amount of track mileage to prove it was safe and viable,” said Priestley.

“Today you can’t do that very easily. You can only do that on a Friday or on a rig in your factory. So it’s another are that they may well have been able to gain is just by bolting parts onto a car, new parts that are coming through, they may have been able to sign quite a lot of stuff off.”

Mercedes are known to have covered 1,000km in the test – more than three Grand Prix distances. “They’ll have had an enormous advantage in terms of proving reliability on any parts,” he added.

“They’ve had some issues with the hydraulic suspension they’ve got so just getting track time on those things will also have been an enormous help. They may have tweaked that system, for example, to overcome any problems they’ve had recently, and they’ve had a three-day test where they may have been able to prove that out, where other teams just don’t get that opportunity.”

Investigating driving styles

For Priestley, the most significant detail about Mercedes’ test was that it involved both their race drivers, Lewis Hamilton and Nico Rosberg.

“From Mercedes’ point of view however it’s come about, whether they think they had permission or they’re just trying to pull a bit of a fast one I’m not sure, but the fact that they used both of their current race drivers – particularly the fact that they used both of them – is a big tell for me that they had an awful lot to gain from this.”

“It wasn’t just a case of doing something for Pirelli. They could have easily got Anthony Davidson or somebody in there, which would also have been useful for them to gain correlation between the simulator work and the real car.”

“There’s lots of things they could have done just to help Pirelli out but the fact that they split the days between their two 2013 race drivers to me says an awful lot.”

Having the regular drivers conduct the test straight after a race weekend gave Mercedes the chance to investigate how different driving styles affect the life of the tyres: “We all know at the moment one of the big things with tyres is the way that the drivers use them, the way that they handle the car, it’s not just about car operation,” Priestley explained.

“I think they will almost certainly have been able to gain quite significantly by having those two guys in a car with all of these things logging tyre temperatures, tyre pressures, all of the different things they will have been logging. They almost certainly will have had thermal cameras, infrared sensors, temperature sensors. They obviously have their tyre pressure sensors and everything else that they normally have.”

“They’ll have been able to, over a course of a ten lap run, whatever tyres they’ll have been running, they’ll be able to monitor how different driving styles affect all of those different parameters.”

During races drivers receive information from their engineers on how to alter their driving style to improve tyre performance, based on what they’re learned previously.

“Those are things that you don’t get much of an opportunity to test out. On Friday at Grands Prix is your only chance and of course there’s so many different things to try out on those days.”

“So to have the chance to do it, also the chance to do it at a circuit where they’ve just gained three days of data from the race weekend so it’s all relevant, all directly comparable, I think they’ll have had an enormous advantage in that sense just by letting the drivers try different things at different points on the circuit and seeing if things behave differently that they have done in the previous three days over the course of the race.”

“It’s such a rare thing to be able to have that chance. I think they will have gained tremendously from that, from a driver point of view.”

Ferrari’s test

Much of the scope Mercedes had to make gains during their test came from the fact they used their current W04 car. Ferrari’s test was conducted using the 150?�?? Italia which last raced in 2011, which Marc believes means they will have learned “considerably less”.

This is in part because although today’s car reach similar levels of downforce as seen in 2011, they rely less on blowing exhaust gasses into the diffuser to achieve them.

“Although we are reaching the same downforce levels now without the blown diffusers, it’s not the same,” said Priestley. “The blown diffuser has great impact on downforce but it was a very slightly different effect.”

“As you can imagine the blown diffuser was giving levels of downforce at different points on the track to what we have today. I don’t think anyone’s going to get, in terms of that Ferrari test, the same sort of advantage as Mercedes. I’d say a world away, to be honest.”

But there was still scope for Ferrari to glean some useful data from their test: “They can still bolt sensors onto the car, if they’ve got new sensors that they want to try out they can still put them on, they can still get mileage onto certain parts – there are some some parts which will carry over from 2011 to 2013. Probably not major suspension items but electrical boxes or wiring harnesses or perhaps they can put a wing on – something they just need to get mileage on.”

“You can certainly run things like 2013 software on a 2011 car. The engines, I presume, are not an enormous amount different, so things like small tweaks or reliability things they want to check out with the engine, I’m sure they could do things like that.

“There’s nothing in the rules to say you can’t put a 2013 electrical component on a 2011 car.”

“The rules permit running a two-year-old car which is what Ferrari did, so in that sense there is nothing beyond that which says you can’t run a 2011 car with a 2013 front wing on it, for example, it doesn’t actually specify that in the regulations.”

Priestley is convinced that Mercedes’ test proved far more valuable than Ferrari’s: “I’ve no doubt it was a huge advantage to them.” The question is whether the FIA agrees, and believes Mercedes broke the rules to gain that advantage.

Mercedes and Ferrari Pirelli tyre test row

Images ?�?� Daimler/Hoch Zwei, Ferrari spa