[Angel Arroyo]

Can some one help me with fuel amount needed for the race at Road America ?

[Angel Arroyo]

I got it about 30 to 31 liters.

[Simon Meisinger]

What’s with that question all the time? Do two consecutive laps and AC tells you how much you need, add some more to be safe and you’re done.

[David Iglesias]

You can calculate easily the total laps of the race dividing the time session between the best lap time of the qualy.
For example, let's say 20 min race and a time of 1:46 for the poleman:
2000 / 146 = 13'6 laps, so you should use fuel for 14 laps to be more than safe, thinking that the race times won't be as fast as qualy times.

There is also an easily way to calcule it: download the fuel app from RaceDepartment, it will show you how many liters do you need to finish the race.

[Russell Sobie]

You can calculate easily the total laps of the race dividing the time session between the best lap time of the qualy.
For example, let's say 20 min race and a time of 1:46 for the poleman:
2000 / 146 = 13'6 laps, so you should use fuel for 14 laps to be more than safe, thinking that the race times won't be as fast as qualy times.

There is also an easily way to calcule it: download the fuel app from RaceDepartment, it will show you how many liters do you need to finish the race.

You broke all sorts of stuff in your math above.

20 minute race is 20x60 seconds, or 1200 seconds. 1:46 lap time is 60+46 or 106 second lap time. 1200/106=11.3207, so 12 or 13 to be safe. Your math comes close, and is luckily (in this case) on the safe side, but it's a teeny bit high. I've been doing it long hand like the above this whole time, and I'm actually surprised for timed races AC doesn't do the calculation for you without an app. 

I think I installed the Fuel App at one point and just forgot to enable it... so I should probably look into that.

Or you can just go here on your phone (googled for this and actually found a post here on the SRS forums): http://fuelmanager.tk/

Edit: Did some minor testing, and this web app looks like it tends to be a bit on the safe side as well. For instance, lap time of 45 seconds and a duration of 50 minutes would give my math 66.667 laps, so I'd say 68 minimum, and his app says 68+1 laps. I guess he has some variance in his algorithm to account for relatively long races with short lap times? 50 second lap times at 20 minutes I get exactly 24 laps (25 for safety) and his says 25+1 laps. Essentially I would recommend using this website. Or just do the calculations yourself. With 60 seconds in a minute, of course.

[Tim Cullingworth]

You could always do a practice at race distance and see how much fuel you use.

Though the idea of practising that long seems to much for some racers on here

[Russell Sobie]

Nice dig (I agree).

However, some folks race in so many different series that doing a 20 minute test race offline AFTER doing enough laps to experiment and get comfy with a particular setup is simply too much time to devote. Given the typical lap time margins on here, I don't thinkthat having 2-3 liters more fuel than you absolutely need to barely cross the finish line is going to slow you down enough for an extra position. I make it a point to use my race setup for qualification, do my manual calculation based on laps done in qualifying, and then just add 2-3 liters to whatever I come up with. I've crossed the finish line on empty one too many times (twice since I started racing in SRS)!