What game?
If it's only 1 hour (1 hour is a sprint really) just take it like every other race. Depending on what game it is request a pit stop a lap before your going to pit. Practice your pit entry, if you want your fuel to go that little bit further, turn your RPM down and learn how to low rev while driving fast, but that is not too important in a 1hour race, that sort of thing comes more into play with a 8 hour + race. (you can save your self a pit stop over your rivals in a 14 hour or so race by revving @ 6000rpm rather then maxing the rpm out @ 8500rpm for example)
What car is it? you could make the full race without a pit stop as it's only 1 hour depending on the fuel tank.