So it doesn't work. I keep adjusting my strategy so that I don't change wheels, and only refuel for the last lap. I click save and then the animation plays of my car pitting, and then stuff is happening for a really really long time ( estimate in the menu said I think 2 seconds) and then i leave having lost like 5 positions!
I got it to work for myself
Make sure you go to the pit strategy menu before the race and activate your desired strategy (triangle). By default, the game always selects the strategy at the top of the menu.
Make sure tire change is set to NO.
Put fuel all the way to zero.
With these settings, the pit stop time should be 0.00. If you change tires, the minimum time is 16.60 seconds.
Now, if you look at the fuel fill meter, you should see the left part of it as a darker grey. You can increase the amount of fuel added in a stop within that dark grey area, and the pit stop time still stays at zero.
That said, even if you have tires put to NO, and add zero fuel, there is still a "minimum stop time" that the car will sit still in the pit box for (it's weird, but that's how it is). This minimum time is about 3-4 seconds.
For online races with a mandatory stop, I set my pit strategy first. I almost never switch tires, as it's not needed in most online races, unless tire wear is set very high. I then look at the dark grey area of the fuel bar, and see how much fuel I can add while still keeping the pit stop time at 0.00.
Once that is set, I go to the tuning menu, and set whatever fuel load I require to make up the difference.
Eg. Let's say I'm doing an 8 lap race. Then let's say the dark grey bar allows me to add 2.3 laps worth of fuel (note: this dark grey bar seems a little glitchy, and changes from race to race, so keep an eye on it). Based on that, in the tuning menu I'll put the race fuel at about 6 laps, or just over, since 8 - 2.3 = 5.7. I like to try to give myself about a .5 to 1 lap buffer with the fuel, just to be on the safe side (and I have yet to drive a car where 1 lap's worth of fuel really makes a difference).
This strategy allows me to run the minimum amount of fuel in the car at any given time while still keeping the pit stop at 0.00 seconds (which, in practice, ends up being about 3-4 sec).
Something else to keep in mind, if Damage is turned on in any sort of way, and if your car has any sort of damage when you come into the pits, the game will fix the damage by default. There is no option to skip over fixing damage. This will automatically add a lot of time to your pitstop....sometimes 20-30 seconds or more. Either keep it clean, or turn damage off.
Using the strategy I described above, I manage to keep the majority of my pit stops under 5 seconds...which can gift you a lot of positions and race wins online if the competition doesnt know what they're doing in terms of setting the pit strategy. I've even recieved some hate mail claiming I'm cheating
