News & Media

Fuel for thought

October 30, 2012, Mark Aumann,

Gambling in closing laps becoming more and more frequent

Races that come down to fuel strategy: It's perhaps the one thing that makes fans roll their eyes and crew chiefs pull out their hair. But with smaller fuel cells and more teams willing to take that gamble in the closing laps, it's become more and more frequent.

Winning races because of fuel strategy is nothing new. Back in the early days of the sport, engineers like Smokey Yunick figured out how to circumvent NASCAR's fuel tank regulations by adding an oversized gas line, allowing his car to carry just a touch more fuel than the competition.

But for every driver who beats the odds, there are those who see their hopes of winning sputter and stall.

In the first restrictor-plate race at Michigan in 1970, crew chief Glen Wood correctly calculated that the engine in his Ford used less fuel than the Dodges and Plymouths, and could make the distance on one less stop. Cale Yarborough led most of the race in the Wood Brothers No. 21, only to have the engine expire with eight laps remaining.

Denny Hamlin appeared to be well on his way to the win -- and a commanding lead in the Chase -- at Phoenix in 2010. But his car wasn't getting the same fuel mileage as the competition, and he was the only one not to top off during the previous caution.

"I think before, you had 10 percent of the teams really looking at it. Now, 80 or 90 percent of the teams are looking at it."


Hamlin was forced to make a costly pit stop under green, which resulted in a 12th-place finish -- and completely changed the championship picture. Even though he still held the points lead heading to the season's final race, his momentum -- and perhaps his confidence -- was gone, and a 14th-place finish at Homestead sealed the title for Jimmie Johnson.

Matt Borland, who recently returned as crew chief for Ryan Newman, has seen fuel strategy evolve over time, mainly because anything successful eventually gets copied by everyone in the garage.

"I think the biggest thing is it's always been there [as a strategy]," Borland said. "It's just now, every team's taking advantage of it. I think before, you had 10 percent of the teams really looking at it. Now, 80 or 90 percent of the teams are looking at it."

It seems so simple: calculate the distance covered in one fuel run and divide that by the amount of fuel used. But it's much more complicated than that, because there are a lot of variables to consider. And when the stakes are high -- particularly as the odds of success are low -- it's not always easy for the guy atop the pit box to be certain his driver can make it to the checkered flag.

Even if you get the fuel cell completely full, there's no guarantee of success. How the engine is tuned -- rich or lean -- can affect mileage. If the car is running out front or back in traffic. Whether the handling is off. If the tire pressures have changed. How proficient the driver is at feathering the gas. Even the weather can be a factor, if it goes from cloudy to sunny during the run, or the opposite direction.

Johnson's crew chief, Chad Knaus, said because the competition is now so equal, having a strong fuel mileage program is imperative.

"It's a necessary evil," Knaus said. "We've said it time and time again, about a third of the races come down to fuel mileage. It's not something we always had to worry about because we were always fast, and were able to do what we needed to do. With the competition now, you have to make sure you're pulling out all the stops at all levels.

"Everybody on the No. 48 team, we work on that more than what we have in the past because it opens up options. You've got to have options when you have competition as tough as what it is."

While crew chiefs are more cognizant of fuel mileage, so are the drivers. With skillful use of the accelerator, they can stretch a full fuel load enough additional laps to race completion.

But it's not easy to learn, especially when the mindset is to go as fast as possible whenever possible. But Johnson knows this Chase could come down to a fuel economy run -- and he needs to be prepared for that eventuality.

He readily admits fuel mileage isn't his strength, while challenger Brad Keselowski is one of the best in the garage.

"Dover turned into a fuel mileage race, which isn't the best for us," Johnson said. "It certainly plays into [Keselowski's] hands. With the final three tracks, two of them, if not all three of them, we can see that.

"We're working hard to play that game if need be. I think we're better at it than we were even at the start of the Chase."

It's fuel for thought.