Return of the slick pitstop

With the ban on refuelling for 2010, fast tyre changes once again become key – and could be the deciding factor in a Grand Prix
By Adam Cooper

Take a look through the 2010 FIA Sporting Regulations and you can almost miss it, but Article 29.1.c is set to turn Grand Prix racing on its head this season. The simple sentence ‘fuel may not be added to nor removed from a car during a race’ has created a huge challenge for all the Formula 1 teams, and it will utterly transform the way strategies unfold.

Refuelling was with us from 1994-2009, and the threat of a catastrophe was always present. In addition there were dozens of occasions when drivers lost positions as a result of rig malfunctions, which very often were not the fault of the team.

Now that’s all consigned to history, but pitstops are not, at least in dry races. Drivers will still be obliged to use both the prime and option tyres at some stage, and thus they will change at least once.

There is no maximum fuel tank size in F1, but hitherto teams typically built their cars to take around 85-90kgs. The key consideration was how much capacity to build in for those races where one stop, and a long first stint, required maximum range.

Now the cars have to start with enough fuel to go the full distance at the highest consumption tracks, namely Valencia and Montréal. The typically quoted figure is around 175kgs, although it varies between the different engine manufacturers.

Within the constraints of the FIA freeze, engine departments (and their fuel suppliers) have worked hard over the winter to optimise consumption. The Cosworth customers had the most difficult decision, because they had to design their cars before the updated V8 – notorious in its 2006 guise for its high consumption – had even run.

Fuel economy will play a part in races too. If one driver sits on the grid with 170kgs in his car, and the guy alongside requires 180kgs to reach the flag, there’s a clear lap time advantage, albeit one that becomes proportionately smaller as the race goes on. Driving style also affects consumption, and those who are able to keep up a pace while using less fuel will benefit.

All that extra fuel has to go somewhere, and teams have had to make their chassis longer and wider to accommodate it. Great thought has gone into how the fuel load drains away, and thus how the centre of gravity changes. Nevertheless, the balance change from a 175kg load at the start to near zero on the last lap will be significant.

Drivers who are a little too fussy and like a car that is ‘just so’ may struggle to cope with the change, and that’s not even accounting for any deterioration in tyre behaviour.

Tyres will be much more of a focus this year, for a variety of reasons. Bridgestone has narrowed the fronts by 20mm, a change that it wanted to make with the move to slicks last year, but which the teams resisted because they had already begun to design their cars.

Less rubber on the road clearly puts more stress on those fronts, and that change has coincided with the massive weight increase, which will be particularly hard on the rears. Meanwhile, the refuelling ban pushes teams towards much longer race stints. It’s helped create something of a perfect storm…

Bridgestone has introduced new constructions to help deal with all this, but the company has admitted that 2010 downforce levels are already up on expectations, so things could prove to be more marginal than anticipated.

So how will races unfold in 2010? No one really knows. In theory the single stop could take place anywhere from the end of the first lap to the start of the penultimate lap. Whether any tyre can last for 69 or 70 laps at a given venue is another question.

A first-lap safety car is bound to encourage those with nothing to lose – especially quick guys starting near the back – to jump into the pits and change. If they are right at the back, they could even put on the less favourable option tyre for a single lap behind the safety car, and then come right back and put primes on before the green flies.

“If you’re at the back you’ll take more risks, because you’ve got nothing to lose,” says Williams technical director Sam Michael.

The further into the race we get, the higher the probability that a safety car will send the entire field into the pits as one group. And that could get a little crowded…

The strategy question was made more complex by a rule change that was only confirmed in February. The 10 drivers who make it through to Q3 will have to start on the exact same set of tyres on which they qualified. So for race fuel loads in 2009, read race tyres. Just as in the recent past the guys in that final session had to make a call on how heavy to run in qualifying, now they will have to decide whether to take the softer option tyre, or the harder prime.

The former will almost certainly earn a better grid position, the latter will provide a more consistent, and potentially longer, first stint. That call has to be made during the heat of battle in Q3, while keeping an eye on what the opposition is doing.

In the past drivers who just scraped into the top 10 often took heavy loads and settled for ninth or 10th on the grid, and they might now take the conservative tyre and let others battle for pole. Those outside the top 10 have a free choice that they can make at the last minute before the start, and they can react to the decisions made by the Q3 runners.

The tyre rules do not apply if qualifying or the race is wet, but rain will create a special set of circumstances on Sunday. Previously teams juggled the switch from full wets to inters to slicks around their fuel stop schedules. Now it will just be about the tyres. Indeed if the track stays wet, and a driver can make his tyres last, a race could be won with no pitstop at all.

The stops are going to be spectacular. Until now the mechanics involved in the tyre change would complete their jobs and then wait for the refuelling to finish, because that’s what determined the length of the stop. Now it’s all down to the tyre guys, and they will be under massive pressure to get it right and send their car back out in under three seconds. Teams have practised hard during the winter, but there are bound to be costly mistakes. Mechanical jacking systems are not allowed.

Wet or dry, race strategies will remain fluid, and there will be times when two stops will be the better route. The key thing is that teams are no longer committed to stopping when their fuel is used up, as Ross Brawn explains: “I think the main issue is it’s going to be a reactive strategy this year, rather than a thought-through, proactive or planned strategy.”

Perhaps the most significant change for 2010 is that the crucial third qualifying session will be about pure speed, with drivers gunning for pole on near-empty tanks. For too long the quest for pole has been compromised by race fuel loads playing a part, and the record books don’t acknowledge the fine details. Once again we will see who really is quick.