Martin Truex Jr. knows what lost him the Daytona 500.
It wasn’t a crash, pit stop strategy or a faulty lug nut.
It was the air.
More specifically, how the air surrounding his No. 78 Toyota reacted when it was side-by-side with another car coming to the checkered flag.
This is also known as side drafting and it kept Truex from being the “the 2016 Daytona 500 winner” for the rest of his life.
“Apparently I’m not that good at (side drafting) because I lost the Daytona 500 by about a foot,” Truex told NBC Sports in May. “Because I side drafted past the 11 car too quick.”
The driver with the title of Daytona 500 winner for the rest of time is Denny Hamlin, who won his second points race at a restrictor-plate track (in addition to 10 top 10s and four exhibition wins).
Hamlin benefited from side drafting, which serves two purposes - speeding you up, or slowing someone else down.
“It’s a momentum game,” Hamlin told NBC Sports. “Essentially, whoever’s nose is out front is at a very big disadvantage.”
Drivers describe it as getting their car close enough to a rear-quarter panel of another. That disrupts the air flowing over their competitors’ car and sends it on to the rear spoiler or into the wheel wells, slowing that car. That allows the car doing the side drafting to pull even or ahead.
With being a momentum game, drafting works both ways. While it can put one car ahead of the other, it can keep the field stagnate, creating the familiar sight of pack racing around the 2.5-mile surface at Daytona.
“So that’s why when you see cars get side by side, it’s hard for anyone to kinda break free,” Hamlin said. “Because essentially once you get the advantage, he’s dumping the air back on your spoiler.”
Though he’s won two plate races in the last three years, Hamlin believes there’s “really no one that stands out” among the rest when it comes to the ability to draft. But Jimmie Johnson, a five-time winner in points races on plate tracks, knows which name to invoke when it comes to pioneer of the draft.
"(Dale) Earnhardt Sr. had that stuff figured out before anyone was even talking about it,” said Johnson of the seven-time Sprint Cup champion.
“The Intimidator” won 10 times at Talladega and three points races at Daytona. He also claimed 10 straight wins in Daytona 500 qualifying races and won the Sprint Unlimited six times from 1980-95. Earnhardt’s final Sprint Cup win came at Talladega in 2000 when he took his No. 3 Chevrolet from 18th to first in the final five laps of the fall race.
Johnson says there’s a “fine line” between who is good at side drafting at superspeedways and the numerous 1.5-mile tracks that populate the schedule.
“Superspeedway racing, be as aggressive as you can be,” Johnson says. “Mile-and-a-half tracks, you gotta be very careful because you can cause a wreck.”
One driver everyone knows is good at side drafting is Dale Earnhardt Jr. He has ridden the draft to 10 combined points wins at restrictor-plate races, including last year’s Coke Zero 400.
“Side drafting used to be something you only saw a handful of guys take advantage of constantly in the ‘80s and ‘90s,” Earnhardt told NBC Sports. “The rest of the field wasn’t as aggressive. But now at the plate tracks the cars that we have today very easily stuck together.”
With its widespread use, Earnhardt says side drafting has become “a limited tool” when everyone in the field is trying to take advantage of it at the same time. The two-time Daytona 500 winner attributes the new-found aggression partly to the car configurations.
“Something about the way the air moves and the fender flares on the front and the back quarter (panels),” Earnhardt said. “Something about these cars have them drafting in such a way that it makes everyone have to be incredibly aggressive with side drafting lap after lap.”
There is such a thing as being too aggressive. Just ask Truex, who has to call someone else the winner of the 2016 Daytona 500.