In this NHRA category, cars have short wheelbases and a fiberglass replica of a production car body. The engines are in front of the driver. The fuel cans a pit crew member wields to refuel a stock car weigh about 100 pounds each when full. Typically the gas man empties two fuel cans during a pit stop. The gear ratio determines how many RPM's the engine turns and thus how fast your car will go.
Gear ratio can also determine how much fuel the car uses.