[James Blint]

You can save the first preset in the pitstop tab before the race, so you don't have anything else to do. Or assign 2 buttons (down + right) to your wheel to set it on the fly, by default you can also do it simply with your keyboard's arrows. On a T300 i just use the dpad, works fine so you can adjust how much fuel you want to add, as well as eventually compound and tyre pressure. It's a bit distracting to do that while racing, except maybe if you have a very long straight.