The biggest problem is just the sheer weight of the fuel – it obviously increases the stopping distance quite considerably. Running with high fuel puts demands on braking – and it means you have to design the brake discs and pads to overcome that. And with a narrower front tyre, you'll lose grip, which will change the fundamental balance of the car. So we've looked at weight distribution, aero balance and mechanical balance in order to compensate for grip balance moving rearwards.
Do you think the banning of refuelling and its effect on the car's tyres and balance will spice up racing in 2010?
It could make the show significantly better, yes. Previously, you knew when everyone was going to stop and refuel, so each team based their strategy decisions on overtaking cars during the pit-stops. What's changed for this year is that we won't know when people are going to stop. The only thing affecting drivers' mandatory stops now is that they have to run both the 'option' and 'prime' tyre, so the strategy choices will be less predictable and will become a little more complicated. Races could be one or two stints with both early and late stops for tyres. And it will definitely make the racing more challenging and interesting – and, hopefully, it will promote more on-track overtaking and less overtaking during the pit-stops.
Finally, what's on your job list going into the four crucial pre-season tests?
Initially, the most important thing is proving that the car is robust. Just about everything has changed on the car, there's very little that hasn't changed, so we want to make sure we're fully reliable for the first race. At the start of 2009, there were teams who were more competitive than us, but we were still able to pick up a good number of points because we were more reliable. These tests will be about establishing the durability of the car and giving ourselves enough time to fix any issues we encounter. In addition, we also want to get a very thorough understanding the new tyre, its degradation and durability, and how to get the best out of it. Beyond that, it'll be about performance development.