Everyone who drives a car has certainly gone through the process of filling up their gas tank many times. However, nobody at a normal gas station has ever had the experience of filling their gas tanks like NASCAR does during a race. One of the keys to winning a NASCAR race is not wasting any time during pit stops. One way that NASCAR drivers make this happen is to keep their cars running when their gas tank is being refilled.
When filling up a normal car's gas tank, it is common to turn your car off to prevent any possible fires from spilled gas. However, NASCAR pit crews train hard and have all their equipment ready so they do not need to worry about spilled or overflowing gas. A few extra seconds at a pit stop can be the difference between winning and losing, so the pit crews put in a lot of effort to make sure the driver does not need to turn off their car during a refuel.
One key piece of equipment that pit crews have at NASCAR races is a dump. A dump is a type of fuel can that is designed to empty everything in it into the race car in under eight seconds. One dump can hold up to eleven gallons of fuel, so two whole dump cans are required to fill a NASCAR race car's fuel tank. If the pit crew knows they need a whole tank, they will empty two dumps into the car, but they also could just put one depending on what time of the race it is to save time. This system makes it much less stressful for pit crew members to pump gas into the car, and because they know the exact amounts of fuel they have, there is no risk of overflowing the tank and causing a fire.
While there is a risk of overfilling your gas tank at a normal gas station, there is nothing normal about a NASCAR pit crew refueling a race car. Pit crews are trained to know how much gas to put in the race car and almost always have a system in place. Using these systems they put together, filling the gas tank becomes a seamless process that may look easy on television, but requires lots of practice and effort. With pit crews knowing exactly what to do, drivers do not need to spend the extra seconds waiting for their cars to restart. Once the pit crew is done, the driver can speed away immediately.
However, if the race car was turned off, they would have to wait a few seconds before they could re-enter the race. Drivers trust that their pit crews will not overflow their gas tanks, so leaving their car on during a pit stop only makes sense, as they want to spend as little time in the pit as possible. Saving time is always key in NASCAR races, and leaving the car running while refueling only helps with that.