How Many Horsepower in a NASCAR?

Nothing quite beats the adrenaline rush of watching a NASCAR race. But how much of a punch do the cars' engines really pack?

While the older Generation 5 and Generation 6 cars sparked criticism, the Next Gen NASCAR Cup cars boast 510 horsepower on the superspeedway package and 670 for intermediate and road course packages. Why? To keep racing as exhilarating yet as safe as possible.

We'll uncover the reasons behind the increased horsepower and even discuss the most powerful NASCAR engine in the following sections. 

Generation 5 and Generation 6 NASCAR Horsepower

Everybody from the fans to the manufacturers to the teams found faults with both the Generation 5 (Car of Tomorrow) and Generation 6 cars.

They looked generic stacked against their street-legal cousins, especially the Generation 5 characteristic raised and winged spoilers.

But the major complaint was the lack of downforce. With increased downforce comes slower speeds, so NASCAR wrestled with ways to combat these problems. The solution? More powerful engines.

Past NASCAR engines could reach a whopping 850 horsepower. However, the company added restrictor plates to the automobiles at superspeedways which limited vehicles to a mere 410 horsepower. 

How Many Horsepower in a NASCAR Next Gen Cup Series Car?

So, that begs the question — how many horsepower in a NASCAR Next Gen vehicle? Luckily, it's far superior to the restrictor-plate-mandated versions.

The Association improved downforce and aerodynamics to create two packages for 2022:

• Superspeedways spec — It boasts 510 horsepower and calls for 7" spoilers. The hiked horsepower means the cars can maintain extra downforce without giving up the hair-raising speed the fans adore. 
• Intermediate and road course spec — With this package, NASCAR applied a jaw-dropping 670 horsepower and 4" spoilers. However, they introduced the tapered space. Think restrictor plates but 1" thick instead of only ⅛" thick. Plus, the holes are tapered, allowing the engine more gas and air than the previous plates.

Thanks to the major improvement from the 2019 package, the 2022 NASCAR season is set to be a blinder. You certainly won't want to miss it!

So, Is the Next Gen Package Safe?

Safety is paramount, especially in such high-speed environments. The Next Gen vehicles underwent a plethora of crash tests where a dummy was placed inside the cabin.

Worryingly, rumors arose that the car failed the crash test. However, NASCAR has vehemently defended itself against these allegations, providing the results were comparable to their previous non-Next Gen safety checks.

The National Association for Stock Car Auto Racing, LLC has a fantastic reputation for vehicle safety. No racer has lost their life in any of the Association's top three Series since 2001.

Other Engine Checks and Inspections

Besides the crash test, NASCAR runs several inspections and tests as soon as the engine is assembled. They're conducted in this order:

1. Dynamometer — This measures the engine output. It's run for half an hour on this machine to break it in. Afterward, someone inspects the engine, checking filters for excess shavings to ensure no excessive wear.
2. Second dynamometer run — If it passes the first time, it goes back on the contraption for two hours. Here, the ignition timing is fine-tuned to maximize power. The operator cycles the engine through a myriad of speed and power settings.
3. Thorough inspection — Finally, they pull the valve train, inspecting the camshaft and valve lifters. Cylinders are checked for abnormal wear before they're pressurized and the leakdown is measured to see how well it holds. Finally, the lines and hoses are evaluated. 

Provided the engine passes all the checks, it's ready to head to the races. After all, NASCAR has a reputation to uphold!

How Many Horsepower in a NASCAR Xfinity Car?

The Xfinity cars run between 650 and 700 horsepower, so they're relatively similar to the Cup Series models. With an engine displacement of 358 cubic inches and a V8 pushrod, the speeds are near identical. 

In fact, if you turn to a Saturday Xfinity Race, you probably can't spot any vehicular differences unless you possess intimate stock car knowledge. There are, however, a few minor variations.

Xfinity vehicles have smaller wheelbases and weigh roughly 100lbs less than their Cup Series cousins. But still, the speeds are neck-and-neck. 

A Cup Car VS Xfinity Car Speed Comparison

Wondering how we know the speeds are similar? Well, let's look at the 2022 Daytona pole sitters. 

Hemric won the pole at the 2022 Beef with a qualifying speed of 49.221 seconds. In the Cup Series, Kyle Larson pipped a speed of 49.680 seconds, almost matching the Xfinity Series pole winner. 

How Much Horsepower in NASCAR Trucks?

Again, NASCAR tracks range from 650 and 700 horsepower, which is very similar to the Cup and Xfinity cars. When restricted, they have 450 horsepower, matching the Xfinity Series vehicles. 

Aesthetically, NASCAR trucks differ significantly from the Cup and Xfinity Series. They feature a wider wheelbase than both. 

What Was the Most Powerful NASCAR Engine?

The most powerful NASCAR engine packed a meaty punch at over 900 horsepower with a V8. It debuted in 2007 in the Chevrolet R07 and was designed exclusively for the Association. 

The Dodge Daytona and the Plymouth Superbird, prime picks in the '60s and 1970, featured the Hemi engine, which allowed the former to reach the groundbreaking speed of 200 mph. No wonder it caught NASCAR's attention! Although, they later banned the engine from its races.

In 1964, the engine won 26 out of 62 races. But sadly, we're only left to wonder just how powerful the Hemi could've become. 

That said, the current Next Gen packages are more impressive than their recent predecessors, but they certainly aren't the most powerful.

NASCAR has welcomed a variety of strong engines. However, the sheer strength forced them to introduce specification mandates to ensure every racer had a fair shot.

The Bottom Line

This season's NASCAR vehicles pack a 670- and 510-horsepower punch — enough to make anybody's hair stand on end! They're far more powerful than their Generation 6 counterparts, promising endless nail-biting races.