How do NASCAR teams balance fuel efficiency and speed? Explained

Fuel efficiency is of extreme importance to NASCAR. The correct or incorrect idea of it can make or break a driver's season, and a team's success story. A perfectly measured fuel capacity can take a driver to the finish line, while a wrongly calculated fuel efficiency can stop the car ahead of the final lap, and ruin the race.

Over the years, the sport's engineers have figured out how to balance fuel efficiency with speed. They cannot afford to use more fuel as it will slow down the car. To make cars faster, they cannot do things the other way around either, as it would increase the risk of losing the race on the last lap due to an empty tank.

Therefore, the NASCAR teams have a pretty good idea of just how much fuel their cars need to have to cover the race on any given day. In today's article, we'll delve deeper into how NASCAR teams balance fuel efficiency and speed.

Standard calculation

The weight of a standard fuel dump is nearly 95 pounds, and it can hold 12 gallons of racing fuel when it's full. A gallon of racing fuel typically weighs around six pounds but can vary due to the temperature change.

Fuel dump cans are weighed once before and once after refueling to get an idea of how much fuel enters the car. If the can weighs 30 pounds after refueling, then 10.8 gallons of fuel is dispensed into the car.

Then comes the standard calculation of (95 pounds - 30 pounds = 65 pounds. And 65/6 = 10.8 gallons.) After the calculation, comes the most vital part – race distance calculation.

According to NASCAR.com:

"To determine fuel mileage at that point, a NASCAR team would divide the amount of fuel replaced into the number of laps completed since the last fuel stop – for instance, if it had been 45 laps, then 45/10.8 = 4.15 mpg."

Despite such a methodical procedure, determining the amount of fuel in a car's tank or how far it can go at any given speed is at best an educated guess. The actual result may vary given variables like dirty air or clean air, weathered tires or fresh tires, etc. In a nutshell, the teams try to be prepared with the data to figure out the best possible way to balance fuel efficiency and speed.

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NASCAR drivers who faced the consequences of wrong fuel efficiency and speed calculation

Brad Keselowski spins out in celebration after winning the Kobalt Tools 400 at Las Vegas Motor Speedway. - Source: Imagn

In 2014, Brad Keselowski scored his first win of the season, after he overtook Dale Earnhardt Jr. to claim the victims in Las Vegas. Earnhardt Jr., the then-HMS driver ran out of fuel on the last lap.

“We weren’t supposed to make it,” the Hendrick Motorsports driver said afterward. “We were a lap short. We tried to save as much as we (could) … make it work, but it didn’t work. We knew we were short. It’s not a shock to us to run out.”

Earnhardt Jr.'s teammate, Jeff Gordon, faced the same fate four months later. Gordon also ran out of fuel under caution at New Hampshire Motor Speedway when the field was preparing for the final restart.