It is always interesting to know which parts of NASCAR vehicles are similar to their stock counterparts, like the location of fuel tanks, and which things are changed drastically in the name of racing efficiency, like the capacity of said tank.
Since it takes gallons of racing fuel to launch cars around the tracks at 200 mph for 3 or more hours, a simple 12-gallon fuel tank that most street-legal cars sport probably won’t keep the engine running for very long.
Since NASCAR race cars have gutted interiors, no air conditioning, and other differences at odds with the everyday models we drive around, it can be hard to find out exact specs on race car parts. Each major race engine builder, Ford, GM, and Toyota, also have their own unique tasks on the fixed regulations NASCAR officials impose on fuel and engine parts.
With all this information, it can be hard to tell just how big a NASCAR tank is and how much fuel can it hold.
How Large Are the Fuel Tanks in NASCAR?
Online sources have listed that a tank of fuel at one point was 22 gallons, but it seems that regulations and fuel cell limits have reduced that volume. Currently, NASCAR engines have an 18-gallon fuel cell limit, and the entire system, including fuel hoses, can hole about 18.5 gallons.
Pit crews and crew chiefs assume 18 gallons of fuel when calculating gallons of race fuel needed for the average 500-mile race.
While 18 gallons may seem like it will get a NASCAR racer further than our 12 gallons tanks, most of our cars average 30 Miles to the gallon, whereas racers are likely to get 2 to 5 miles per gallon. How hard the racer drives the gas pedal, road conditions, and desired lap time are all factors that determine whether 2 or 5 MPGs are more likely. High speeds and rough roads burn fuel at a faster rate than smooth roads and slower speeds.
Less fuel under caution laps is burned, and the lowest fuel consumption is then a racer flows a team member’s draft around the race track. When the drivers reach the pit crews, they use 11-gallon gas cans to refuel the gas tank. It takes a can and a half to top off drivers near the empty tank, and any additional fuel that can be poured in will be to empty the cans of racing fuel.
NASCAR Fuel Info
Traditionally, NASCAR used leaded 104 Octane fuel, which was bad to inhale and left lots of drivers feeling sick after races. A safer unleaded racing fuel was developed in the 2000s, which is a 98-Octane Green E15 fuel provided by Sunoco, the official fuel supplier of NASCAR. This 98-octane fuel is a green fuel and produces far less carbon monoxide than the previous fuel with less environmental impact.
With slightly better mileage, the average fuel usage has gone down a fraction per race, but with the increasing gas prices, no savings have been recorded.
Race teams try to get around fuel regulations by making adjustments that do things like make cars lighter or hold more fuel. As racers found ways to add an extra gallon or two, regulators had to create new laws. Now all components of the fuel tank are regulated from the fuel cells to the hoses to even the temperature of the fuel being added to the car.
All fuel going into the gas tank needs to be at an ambient temperature and not chilled as physics-minded racers have done in the past.
Some examples of skirting the rules are the time Smokey Yunick bought an oversized tank and inflated a basketball during pre-race inspection. When the officials filled the tank and emptied it, the inflated basketball filled the void to create the illusion of a regulation-sized tank.
Once out of sight, he popped the basketball, fished it out of the tank, and added the extra fuel needed to outpace his competitors. When his car lasted much longer than the other races before needing refueling, officials grew suspicious, and he tried other gambits instead.
Smokey also used a 2-inch fire hose as a fuel hose and add 11 feet of tubing to hold an extra 5 gallons of fuel outside of the gas tank’s 18-gallon capacity. At the time, there were no limitations on what types of tubing could be used for fuel, so adapting a large-diameter hose made sense. Another racer Richard Perry ran a fuel line through his roll cage, telling officials it made the interior more organized.
Other racers have artificially inflated the fuel bladders and also ran extra tubing through trunks and other empty sections of the car. Now the NASCAR fuel rules and regulations are more than 4 pages long.
| Fuel Component | Regulation | Function |
| Fuel Cell | 17.75 gallons | Holds the fuel and injection pumps |
| Fuel Hoses | 1/2 inch | Delivers fuel to the engine |
| Fuel Tank | 18 Gallons | Houses all of the fuel components in the race car |
| Fuel | Sunoco 98 Octant Green E-15 Fuel | Gives cars better performance with fewer adverse health and environmental effects |
What Volume of Fuel Is Consumed at a NASCAR Event?
It may seem obvious, but a large amount of fuel is used every race weekend when NASCAR events are held. Evidence of the large amounts of fuel used is the massive 300-gallon fuel tanks visible at events. While the fuel is customized for each event racer, the pit crew is able to fill their 11-gallon refill cans at the supplier pumps on race day.
No stabilizers to prolong fuel life allow gas to burn better than even the highest octane fuel found at common gas pumps.
On average, over 100 gallons of fuel per race is used based on the number of racers participating, the total track length, and if there are extra caution laps. The burn of fuel at race speed is much faster than cars going slower outside of green flag racing. Fuel consumption can be tricky because shorter races do not necessarily mean less fuel consumed since multiple factors affect how much is burned during a lap.
Fuel consumption is affected by the speed of the car, the friction on the track, position in the race, and weather conditions. The amount of fuel burned in the first hundred laps may not be the same as the car burns each lap for the rest of the race. It takes a lot of math to not sell your driver short and give a cup of fuel too little, leaving them stranded before the final lap.
On average, NASCAR uses 3,800 gallons of premium customized fuel per season.
How Do Pit Teams Know How Much Fuel to Use?
Since calculating fuel can be a headache, a lot of work goes into keeping track and strategizing how fuel will be used during races. With the introduction of stages, some teams try to burn fuel early and take advantage of the stage break to fill up, while others save most of the burn for the last stage.
Pit teams need to be able to judge how many miles of race and how many miles the car gets per gallon, then determine what they need on hand for race day.
Based on the capacity of the cars and total race distance, they calculate the estimated gallons per race, which comes out to around 100 gals, and then look at the total tank capacity. A NASCAR fuel tank can hold 18 gallons, so at least 5 pitstops and 10 or more cans of gas will be needed for a driver to complete a standard race.
Miscalculating in the last part of each stage can mean a driver carries more weight around the track than is needed or, worse, stalls before the end of the race
A good pit team will balance the weight of fuel with enough gas to finish each stage of the race so the driver will not be overloaded. It usually takes at least one full can to power a car from the final pitstop to the checkered flag. On race days with drastic temperature changes, pit crews need to be even more aware of fuel density changes that could leave them SOL.
For most teams, however, the 18-gallon NASCAR gas tank is kept full enough to get their driver to the finish line.
