NASCAR Engine Power

A look at the engines fueling NASCAR’s three national series

When it comes to speed, power, and pure American muscle, nothing captures the essence quite like a NASCAR engine. Across its three national series—the Cup Series, Xfinity Series, and Craftsman Truck Series—NASCAR engines are finely tuned beasts built for performance, endurance, and consistency. While each series has its own regulations and goals, the engines powering these stock cars are engineered with precision to deliver maximum horsepower and a thrilling fan experience.

At the top of the NASCAR food chain is the Cup Series, where teams use a 358-cubic inch (5.86L) V8 engine producing up to 670 horsepower on most tracks and up to 510 horsepower on superspeedways like Daytona and Talladega, thanks to restrictor plate regulations. These engines, provided by top manufacturers like Chevrolet, Ford, and Toyota, are built by each team's engine department or specialized builders like Hendrick Motorsports or Roush Yates Engines. Designed for durability over 500 miles and beyond, Cup Series engines incorporate sophisticated valve timing, fuel injection systems, and some of the most closely monitored parts in all of motorsports.

The Xfinity Series, considered the proving ground for future Cup drivers, also uses 358-cubic inch V8 engines, but with slightly less power output. Typically, these engines produce around 650 horsepower and include more cost-effective components to help smaller teams compete. Many parts are similar to Cup cars, but the Xfinity Series places more emphasis on driver development and team strategy, so the engines—while potent—are slightly less advanced in tech and cost. Nonetheless, they deliver exciting racing with raw power and tight competition.

Meanwhile, the Craftsman Truck Series brings its own brand of high-octane racing with uniquely tuned V8 engines. These engines are based on the same 358-cubic inch platform but produce about 600–650 horsepower. The trucks themselves, with their boxier frames and added aerodynamic drag, create different demands on the engine, requiring torque-heavy tuning for short tracks and road courses. Just like in the other series, engine durability is key, especially with aggressive driving and tight pack racing being the norm in the Truck Series.

From the elite Cup Series to the gritty Truck Series, NASCAR engines remain the thunderous heart of the sport. Though the specs may vary slightly between series, all are designed with the same purpose: to create competitive racing, push mechanical limits, and thrill fans. Whether it’s a championship Sunday or a Friday night under the lights, when a NASCAR engine roars to life, it’s more than horsepower—it’s heritage, innovation, and adrenaline in motion.