Fuel strategy and pit stops
Discussion
Can anyone help me understand fuel strategy with respect to grid position etc? How does a team decide exactly what fuel load to run off the start with respect to others? Why when someone qualifies unexpectably further down the grid do they often fuel them long into the race?
Lots of this was going on in Bahrain and I never seem to keep up with it all.
cheers
Lots of this was going on in Bahrain and I never seem to keep up with it all.
cheers
Edited by davislove on Saturday 9th May 18:48
Basically, first qualifying is done on as little fuel as you like, as is second qualifying. Those that get knocked out in these two sessions (two lots of 5 cars) have qualified outside the top ten and so can choose their fuel loads after qualifying.
Those who get through into qualifying 3 have to put their race fuel into the car BEFORE that third session starts, so qualifying 3 is done on much heavier fuel loads, the amount they'll need to get through qualifying 3 then get to the first pit stop in the race. These fuel levels aren't disclosed until after qualifying, so those drivers / teams in the top ten have to make a judgement call, do they fuel light and try to qualify as high as possible but perhaps compromise their race slightly by having to pit early, or do they carry more fuel which is potentially an advantage in the race, but will mean you're slower in qualifying so may start lower down the grid.
The teams will do lots of calculations to work out the quickest way to run the race, which more often than not involves 3 stints (2 stops) with a first stint of about 15-20 laps if you're at the front and arent being held up. This allows you to run reasonably light in qualifying to get high grid positions and gives you good race pace, without compromising your race with an unduly short first stint that may mean after your first stop you havent pulled enough gap on the midfield meaning you come out behind much slower cars that are running longer, and get held up.
The reason some of the faster cars who qualify lower down the grid (say Raikkonen in this race) will often fuel heavy is because they're highly likely to get caught behind slower cars at the start of the race, and regardless of how fast/light the car is, they'll struggle to get past so they can't use all the potential speed. This being the case, they might as well be carrying more fuel so that when those ahead of them pit for their first stops, they have a few laps in "clean air" where they can hopefully put in some faster laps to leap frog the opposition immediately ahead of them, or switch strategy to a one stop if the race pans out in a certain way. A heavy fuel load also gives you additional chances of making up ground if there's a safety car or if it rains, again due to having a much larger pit window to pick the optimum time to come in compare to having say 15 laps of fuel like those at the front.
The downside of this is obviously you're slower so the chances of overtaking people are even less and you may well suffer more tyre wear due to a heavier car and longer stints, so its a balancing act. At the end of the day, a heavy fuel load is rarely the fastest way to complete a race distance in theory, but its often the best "hedge your bets and hope" option for cars lower down the grid that are invariably affected by other cars around them and need a bit of luck to make up significant ground.
Those who get through into qualifying 3 have to put their race fuel into the car BEFORE that third session starts, so qualifying 3 is done on much heavier fuel loads, the amount they'll need to get through qualifying 3 then get to the first pit stop in the race. These fuel levels aren't disclosed until after qualifying, so those drivers / teams in the top ten have to make a judgement call, do they fuel light and try to qualify as high as possible but perhaps compromise their race slightly by having to pit early, or do they carry more fuel which is potentially an advantage in the race, but will mean you're slower in qualifying so may start lower down the grid.
The teams will do lots of calculations to work out the quickest way to run the race, which more often than not involves 3 stints (2 stops) with a first stint of about 15-20 laps if you're at the front and arent being held up. This allows you to run reasonably light in qualifying to get high grid positions and gives you good race pace, without compromising your race with an unduly short first stint that may mean after your first stop you havent pulled enough gap on the midfield meaning you come out behind much slower cars that are running longer, and get held up.
The reason some of the faster cars who qualify lower down the grid (say Raikkonen in this race) will often fuel heavy is because they're highly likely to get caught behind slower cars at the start of the race, and regardless of how fast/light the car is, they'll struggle to get past so they can't use all the potential speed. This being the case, they might as well be carrying more fuel so that when those ahead of them pit for their first stops, they have a few laps in "clean air" where they can hopefully put in some faster laps to leap frog the opposition immediately ahead of them, or switch strategy to a one stop if the race pans out in a certain way. A heavy fuel load also gives you additional chances of making up ground if there's a safety car or if it rains, again due to having a much larger pit window to pick the optimum time to come in compare to having say 15 laps of fuel like those at the front.
The downside of this is obviously you're slower so the chances of overtaking people are even less and you may well suffer more tyre wear due to a heavier car and longer stints, so its a balancing act. At the end of the day, a heavy fuel load is rarely the fastest way to complete a race distance in theory, but its often the best "hedge your bets and hope" option for cars lower down the grid that are invariably affected by other cars around them and need a bit of luck to make up significant ground.
Edited by LocoBlade on Saturday 9th May 22:53
davislove said:
Can anyone help me understand fuel strategy with respect to grid position etc? How does a team decide exactly what fuel load to run off the start with respect to others? Why when someone qualifies unexpectably further down the grid do they often fuel them long into the race?
Lots of this was going on in Bahrain and I never seem to keep up with it all.
cheers
The question is how fast can your car go with lots of fuel. Well, contrasted with a lower fuel level, because when you have less fuel, you need to stop for more, which takes X (say 25 seconds) amount of seconds. So, if your car is say 0.8 seconds a lap slower on full fuel, but goes 25 laps further, then you've made 0.2 seconds a lap.....Lots of this was going on in Bahrain and I never seem to keep up with it all.
cheers
When you are at the back, there is no point being light on fuel because you will get caught in traffic and waste the speed advantage that you would have over heavier fuelled cars (because you are lighter you should be faster) so you may as well fuel heavy, which means you can choose when to stop for more fuel/tyres etc.. so more flexibility so that you can time your fuel stop to come back out into light traffic or even a clear road...
Certain tracks = hard to overtake. So when it comes to the final qualifying position you want to get to the front, so you have to choose whether or not to fuel lighter to get higher up the grid, so that you have less cars in front of you to try and get past.
It's basically a whole load of calculations and variables which are put into the computer to see which strategy gives them the fastest time around the track.
I wonder if that makes much sense..
Jasandjules said:
davislove said:
Can anyone help me understand fuel strategy with respect to grid position etc? How does a team decide exactly what fuel load to run off the start with respect to others? Why when someone qualifies unexpectably further down the grid do they often fuel them long into the race?
Lots of this was going on in Bahrain and I never seem to keep up with it all.
cheers
The question is how fast can your car go with lots of fuel. Well, contrasted with a lower fuel level, because when you have less fuel, you need to stop for more, which takes X (say 25 seconds) amount of seconds. So, if your car is say 0.8 seconds a lap slower on full fuel, but goes 25 laps further, then you've made 0.2 seconds a lap.....Lots of this was going on in Bahrain and I never seem to keep up with it all.
cheers
When you are at the back, there is no point being light on fuel because you will get caught in traffic and waste the speed advantage that you would have over heavier fuelled cars (because you are lighter you should be faster) so you may as well fuel heavy, which means you can choose when to stop for more fuel/tyres etc.. so more flexibility so that you can time your fuel stop to come back out into light traffic or even a clear road...
Certain tracks = hard to overtake. So when it comes to the final qualifying position you want to get to the front, so you have to choose whether or not to fuel lighter to get higher up the grid, so that you have less cars in front of you to try and get past.
It's basically a whole load of calculations and variables which are put into the computer to see which strategy gives them the fastest time around the track.
I wonder if that makes much sense..
The KERS should be an advantage over those without in such situations - slow car, heavy fuel load, one overtaking spot. It suprised me when BMW dumped it.
A lot of it these days is how well your car works on both sets of tyres. You will be trying to manage a shorteer stint on a sub-optimal tyre than on the optimal compound. The car may work the tyres too hard if it is brimmed with fuel so you may be limited as to how long you can run for as a maximum without compromising yourself in the race. If you can't go above a certain mileage without degradation an the better compound you will have to look at how fast the tyres drop away, compared to how much time you will lose on the worse compound.
A car that can use both compounds of tyre well and is easy on its tyres will be at a distinct advantage.
I believe that being easy on the tyres is one of Brawn GP's main advantages this season.
A car that can use both compounds of tyre well and is easy on its tyres will be at a distinct advantage.
I believe that being easy on the tyres is one of Brawn GP's main advantages this season.
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