The point of drafting in NASCAR is to reduce aerodynamic drag, allowing cars to go faster with less engine power by using the slipstream (low-pressure wake) of the car in front, which saves fuel, reduces strain, and creates strategic passing opportunities, especially on large tracks like Daytona and Talladega. It’s a form of teamwork where a trailing car pushes the lead car, and in return, both benefit from reduced wind resistance, effectively acting like a single, more powerful unit.
How it works
- Reduces Drag: The car in front pushes through the air, creating a low-pressure vacuum behind it. The following car tucks into this “pocket,” experiencing significantly less air resistance (drag).
- Increases Speed: With less drag, the trailing car can accelerate faster or maintain speed more easily, often going faster together than they could alone.
- Creates Momentum: The trailing car can gently push (bump draft) the car ahead, transferring momentum and helping both to go even faster down the straightaways.
Why it’s crucial
- Power Management: NASCAR cars have powerful engines but are limited by rules (like restrictor plates on superspeedways), making drag reduction essential for speed.
- Strategic Overtaking: Drafting allows drivers to create speed for passing on long straightaways where independent speed isn’t enough, particularly at tracks like Daytona and Talladega.
- Teamwork & Risk: It requires communication and trust, as a push can become a wreck if not done carefully, but it’s vital for success in pack racing.
- Fuel Economy: By reducing the engine’s workload, drafting also improves fuel efficiency, which can extend a car’s race time before pitting.
The physics that makes drafting worth the risk
At NASCAR speeds, aerodynamic drag is the dominant resisting force on long straights. Drag force rises with the square of speed, and the power needed to overcome it rises with the cube of speed. That is why a small reduction in drag can translate into a meaningful change in throttle position, fuel burn, and top speed.
A simplified way to describe the load is:
Drag force equals 0.5 times air density times drag coefficient times frontal area times speed squared.
Power to beat drag equals drag force times speed.
In clean air, the engine must produce wheel power that matches drag plus rolling resistance plus drivetrain losses. In the draft, drag drops, so required wheel power drops with it.
A drafting line can add roughly 5 mph in speed for each car in the draft, which is why partners matter at Daytona and Talladega.
Why the trailing car’s engine works less
The trailing car gains two aerodynamic advantages at once.
First, the lead car has already formed the high energy airflow pattern that “costs” power. The second car sits in the disturbed flow and sees less stagnation pressure on its nose, so the air does less resisting work on the body.
Second, the trailing car partly fills the low pressure wake behind the lead car. That raises base pressure at the rear of the lead car and reduces its pressure drag. In plain terms, the second car helps the first car.
That shared gain is why you see two drivers commit to a line. If both cars stay connected, both can run a speed that neither could reach alone with the same setup.
What drivers do with the saved power
Once drag drops, the driver has a choice, and the choice is strategic.
Option one, hold speed with less throttle
Lower throttle for the same speed means lower fuel flow. Over a green flag run, that changes pit windows and can flip track position. It also reduces heat input into the powertrain, which matters in long runs where temperatures creep.
Option two, keep throttle and convert the gain into speed
The classic passing move is the slingshot. The trailing driver stays tucked in to minimise drag, then pulls out into cleaner air at the last moment and uses the extra speed to clear the lead car.
The key detail is timing. Pull out too early and the car hits full drag while it is still alongside. Pull out too late and the run ends at the leader’s rear bumper.
The trade off: less drag, less front grip
Drafting is not a free lunch. The air that normally builds front downforce is disturbed behind another car. That can reduce front tyre load, create understeer, and force a lift to keep the nose on line.
On a superspeedway, the corners are fast enough that small changes in front load still matter. On intermediate tracks, the wake can be a bigger handling problem than the speed gain, depending on car rules and aero package.
Cooling: the engine load drops, the heat risk rises
Drafting reduces the power required to push through the air, yet it can increase the chance of overheating. That sounds backwards until you remember what the airflow does at the nose of the car.
The same high pressure air that creates drag also provides the pressure head that drives flow through the radiator ducting. When the trailing car sits in the draft, it sees less effective airflow at the grille area, so radiator heat rejection can fall while the engine continues to produce substantial heat.
Modern NASCAR cooling layouts tighten this constraint. NASCAR.com’s technical coverage of the Next Gen car explains that radiator and engine intake air both come from the front grille area, and that teams no longer use grille tape as a control tool. That makes airflow management more sensitive when cars run close together.
The practical driver response is simple. If water temperature climbs, the driver must pull out of line for clean air, even if that means losing the tow and giving away track position.
The small intake pressure penalty, and why it rarely matters
The draft pocket has lower dynamic pressure than clean air. That means slightly less ram effect at the intake mouth, and in theory a small reduction in cylinder fill at wide open throttle.
In practice, the drag reduction is far larger than the intake penalty. The engine does not need the same wheel power once drag falls, so the net performance still improves. Modern engine management also adjusts fuelling to hit target air to fuel ratio as conditions change, which keeps combustion stable even as intake pressure shifts.
Pack drafting versus two car drafting
The geometry changes when more cars join the line.
In a two car draft, the wake interaction is relatively stable. In a pack, each car sits in a different flow field, and small lateral movements can break the seal.
The best lines are the ones with discipline. A small gap opens, air fills it, drag rises, and the whole line loses momentum.
Why drafting decides races at Daytona and Talladega
Superspeedways magnify drafting for three reasons.
- The straights are long, so small speed gains compound into a large closing rate.
- The racing is often pack based, so drivers have partners available.
- Passing often needs a run, not just a faster car.
This is also why track position can be fragile. If you lose the draft, the air becomes your enemy again, and the gap can grow quickly.
The mental side: drafting is trust, timing, and leverage
Drafting is technical, yet it is also a test of nerve. Drivers place their nose a few inches from another car’s rear bumper at close to 200 mph, often while two other lanes are doing the same.
The lead driver holds leverage. They can control pace, choose lanes, and manipulate the air to make the follower uncomfortable.
The trailing driver holds a different leverage. A well timed push can help the leader clear a lane. A poorly timed bump can lift the leader’s rear tyres or unsettle both cars, turning a partnership into the start of a wreck.
Drafting FAQs
What is drafting in NASCAR?
Drafting is when a trailing NASCAR car runs close behind a lead car to reduce aerodynamic drag. The lead car disturbs the airflow and leaves a lower pressure wake, so the trailing car needs less power to hold speed or can use the gain to accelerate for a pass.
Does drafting help the lead car too?
Yes. In a tight two car draft, the trailing car can reduce the low pressure wake behind the lead car. That reduces pressure drag on the lead car, so both cars can gain speed compared with running alone.
Why does a NASCAR engine run hotter in the draft?
The airflow at the front of the car drives cooling through the radiator ducting. In the draft, that airflow can drop, which reduces cooling capacity and raises water temperature. NASCAR.com has also outlined how the Next Gen car pulls radiator and intake air from the front grille area, increasing sensitivity to airflow when cars run close.
What is a slingshot pass?
A slingshot pass is when a driver builds speed in the draft, then pulls out at the right moment and accelerates into clean air to clear the lead car. It relies on the speed gain created by reduced drag while the car is tucked in behind another.
