NASCAR Cup Series cars use a standard 18-gallon fuel tank — this capacity is set by NASCAR itself, and anyone participating in its races must comply with this regulation. This tank size is a bit larger than the average fuel capacity of most modern cars, which hold between 12 and 15 gallons. Advertisement Unfortunately, counting how much fuel one car burns during a race is a bit more complicated to measure. That's because cup cars do not have a fuel gauge; instead, the teams determine how much fuel a car has consumed by measuring how much a dump can weighs before and after refueling. The amount of fuel used in a race also varies wildly depending on conditions and the location. For example, NASCAR's average racing speed at the Michigan International Speedway is about 200 mph. On the other hand, events at smaller tracks with more turns and shorter straights, like the Bristol Motor Speedway, typically average at 125 mph. That means cars running in the latter often consume less fuel compared to when they're racing in the former. Aside from that, cars don't use as much fuel when they're drafting. So, a car running in the middle of the pack would consume less fuel than one in the lead. Advertisement However, we can estimate how much fuel is used in a race by looking at some numbers. We're going to base our computation on the Daytona International Speedway, which has a 200-lap or 500-mile race distance, and a fuel window of about 40 laps or 100 miles. This means a NASCAR Cup Car must refuel at least four times during the race. Assuming that it will go for a full tank at every stop, that means it would have burned around 90 gallons in one race at Daytona.