Managing tires properly is more important than aerodynamic and engine performance in F1 races this season, according to Williams's chief operations engineer Mark Gillan.
Last weekend's Chinese Grand Prix highlighted the fact that this year's tire strategies can make or break a race for a team, and Gillan reckons that not upsetting the tire balance will have a huge influence on getting good results regardless of how strong a car is.
"Tire management is fundamental," Gillan said. "The tires are the number one item on the car, followed by aero and then engine. But understanding the tires and managing the tires is the key to unlocking race performance. Qualifying as well, but of particular performance in race.
"Aerodynamics is still a key driver and better aerodynamic performance and efficiency will deliver more laptime, as long as you don't upset the tire balance, and that's something that's always a factor. It's never not been an issue, but this year it seems to be a particular balance between the two. It's not just the aero, it's a whole mechanical balance."
Gillan says that finding the right balance between tire use in qualifying and in the race is also a key element that Williams is still working hard on to try to improve.
"That's the fine balancing act that needs to be done, and is becoming more important. All teams are working in that direction and we're looking to improve in that direction, too."
Gillan is optimistic that Williams can get its tires working properly both in hot and cool conditions, but admits the temperature changes between qualifying and the races will be hard to manage.
"I think we can manage both, but where it becomes difficult is when you have a big temperature swing, particularly with the parc ferme conditions. In qualifying and the race if there's a big temperature swing, you have to primarily err towards the race and then just a question of how much that temperature swing is in terms of the setup.
"So it's becoming really interesting. In the last race Mercedes and Rosberg did an excellent job. I've never seen it so tight with the chasing pack. It was like lap two or three of the race on every lap."