How Many Horsepower Is a NASCAR Engine?

Today’s NASCAR Cup Series engines produce about 670 horsepower at most tracks, and roughly 510 horsepower at the three drafting superspeedways—Daytona, Talladega, and Atlanta—where the rules mandate a lower-power package for safety and pack racing. Those figures are set by NASCAR’s regulations rather than the engines’ raw potential, and they can vary slightly by conditions and technical updates.

Which NASCAR are we talking about?

“NASCAR engine” can mean different things across the sanctioning body’s national series. The power you usually hear quoted—670 hp and 510 hp—refers specifically to the top-tier NASCAR Cup Series and its current “Next Gen” rules package. The second-tier Xfinity Series and the Craftsman Truck Series use different engines and target power levels, generally in the mid-600-hp range, but the Cup Series figures are the benchmark most fans and broadcasters reference.

Cup Series horsepower by track type

NASCAR manages power output primarily with a tapered spacer and engine mapping, creating two distinct packages depending on the venue. The list below outlines the current norms fans will see during a season.

• Most ovals and all road courses: Approximately 670 horsepower
• Drafting superspeedways (Daytona, Talladega, Atlanta): Approximately 510 horsepower

These numbers reflect the standard packages used throughout recent seasons in the Next Gen era. While teams may see minor fluctuations due to weather, altitude, and dyno variance, these are the targets NASCAR enforces for competition and safety.

Why the horsepower varies

The split between 670 hp and 510 hp isn’t arbitrary; it’s designed to balance speed, safety, and racing quality. Here’s what drives those choices.

1. Safety at extreme speeds: Superspeedways produce very high cornering and straight-line speeds; limiting power reduces closing rates and catastrophic energy in crashes.
2. Aero drafting dynamics: Lower power on drafting tracks encourages pack racing and tighter competition, which is central to the spectacle at Daytona, Talladega, and the reprofiled Atlanta.
3. Competitive parity: Standardized spacers and ECU controls help keep the field closer, shifting emphasis from raw engine output to strategy, tire management, and driver skill.
4. Cost control: Capping usable power discourages an expensive arms race in engine development, a long-time concern for the sport.

Taken together, these factors explain why NASCAR intentionally sets different power targets for different track types, rather than letting unrestricted engines dictate the racing product.

Technical snapshot: What’s under the hood?

Although their output is capped by rules, Cup engines remain highly sophisticated race units with classic American V8 architecture. Here are the key attributes enthusiasts cite.

• Displacement: 358 cubic inches (5.86 liters)
• Configuration: Naturally aspirated pushrod V8, two valves per cylinder
• Fuel and control: Electronic fuel injection with a standardized ECU
• Power management: Tapered spacer and engine calibration to meet 670/510 hp targets
• Manufacturers: Chevrolet, Ford, and Toyota (through their respective racing engine programs)

The combination preserves NASCAR’s traditional engine identity while integrating modern electronics and rulebook controls to achieve the desired power levels.

How we got here

Horsepower in the Cup Series has evolved with safety and competition goals. Earlier packages in the late 2010s split tracks into “low” (around 550 hp) and “high” (around 750 hp) power categories. With the 2022 introduction of the Next Gen car, NASCAR standardized the non-superspeedway package to roughly 670 hp, while maintaining a reduced-power superspeedway package—now around 510 hp—to shape the racing at drafting tracks. Adjustments since have focused more on aerodynamics and tires than on headline horsepower.

Bottom line

When fans ask, “How many horsepower is a NASCAR engine?” the practical answer, for the Cup Series today, is about 670 hp most weeks and about 510 hp at Daytona, Talladega, and Atlanta. Those figures are intentional, regulated targets designed to produce the style of racing NASCAR wants across its varied schedule.

Summary

NASCAR Cup Series engines are governed to approximately 670 horsepower at the vast majority of tracks and about 510 horsepower at the three drafting superspeedways. The split balances safety, speed, and competition, with power controlled via tapered spacers and electronic management on 358-cubic-inch, naturally aspirated V8s. Other national series run different specs, but the Cup numbers are the standard most often cited.

How much HP do NASCAR cars have?

NASCAR’s Next Gen cars have two different horsepower ratings: 670 horsepower (hp) for most tracks, and 510 hp for restrictor plate tracks like Daytona and Talladega. This 670 hp rating is a significant increase from the 550 hp package used for several years prior and is achieved through a standard V8 engine.
 
Here’s a breakdown of the current horsepower levels: 

• 670 hp (500 kW): Opens in new tabThis is the standard horsepower output for NASCAR Cup Series cars at road courses, short tracks, and intermediate ovals.
• 510 hp (380 kW): Opens in new tabAt restrictor plate tracks, such as Daytona and Talladega, a restrictor plate is used to limit airflow to the engine and cap horsepower at 510 hp.

Why the horsepower levels have changed:

• History of Reduction: NASCAR has historically reduced horsepower over time, with cars having over 900 hp in the mid-2010s, then dropping to 750 hp, and then to 550 hp in 2019. 
• Next Gen Car: The introduction of the Next Gen car in 2022 saw horsepower increase from the 550 hp package to the current 670 hp package. 
• Safety and Racing: These changes are made for various reasons, including improving the racing product and ensuring safety. 

Do all nascars use the same engine?

No, not all NASCAR engines are the same; however, they must all conform to strict specifications set by NASCAR, including being a naturally aspirated, 358 cubic-inch V8 engine with a pushrod valvetrain and fuel injection. The three manufacturers—Ford, Chevrolet, and Toyota—develop their own unique engines within these rules, rather than using a single, identical engine for all teams and manufacturers.
 
Key aspects of NASCAR engines

• V8, 358 cu. in. displacement: All engines must be V8s with a maximum displacement of 358 cubic inches (about 5.9 liters). 
• Pushrod valvetrain: Unlike most modern street car engines, NASCAR engines use a traditional pushrod-actuated valvetrain. 
• Naturally aspirated: The engines are naturally aspirated, meaning they do not use turbochargers or superchargers. 
• Fuel Injection: All engines are required to use electronic fuel injection systems. 
• Manufacturer-specific designs: While adhering to NASCAR’s rules, Ford, Chevrolet, and Toyota create their own distinct engine designs. 

Why they aren’t identical

• Manufacturer differentiation: Each manufacturer submits its own engine design for approval by NASCAR. 
• Competition: This allows each brand to develop unique engineering solutions and create a competitive advantage while still adhering to the standardized rules. 

How much horsepower does a 426 Hemi have in NASCAR?

The Nascar-spec 426 Hemi engine produced around 650 to over 500 horsepower in racing trim, though it was officially rated much lower for street versions. The original, detuned 426 Street Hemi was rated at 425 horsepower, but the legendary “Elephant Engine” was incredibly powerful and durable, making it a dominant force in NASCAR and a legendary engine in muscle car history.
 
This video shows a test of the 426 Hemi engine and how it performs: 58sMopar Connection MagazineYouTube · Dec 3, 2023
Street vs. Race Hemi Power

• Street Hemi: Opens in new tabThe 426 Hemi, available in Mopar muscle cars, was rated at 425 horsepower but often produced more in real-world applications. 
• Race Hemi: Opens in new tabIn NASCAR and racing trim, the 426 Hemi was much more powerful, estimated to be producing well over 500 horsepower, and potentially as much as 650 horsepower. 

Dominance on the Track 

• First NASCAR Appearance: The 426 Hemi debuted in the 1964 Daytona 500, where it powered Richard Petty to a dominant victory, showcasing its raw horsepower and durability.
• Decisive Edge: Its combination of strength and horsepower gave Chrysler teams a significant advantage on NASCAR’s fastest tracks.
• Banned from NASCAR: The overwhelming success and power of the 426 Hemi were so complete that NASCAR eventually restricted its use.

How many miles per gallon do nascars get?

NASCAR cars get approximately 4 to 5 miles per gallon (mpg) under normal race conditions, though this can vary based on track type, driving style, and race conditions. Fuel consumption is a critical factor for teams, who use fuel mileage strategies to maximize their car’s performance and range during a race.
 
Factors affecting NASCAR MPG:

• Track Type: Shorter tracks and slower speeds naturally result in less fuel consumption. 
• Driving Style: Drivers who can maintain a consistent throttle and avoid excessive braking, especially around turns, can achieve higher MPG. 
• Race Conditions: Yellow flags (caution periods) extend the fuel window by reducing speed and fuel consumption. 
• Strategic Fueling: Teams often use fuel-saving strategies to extend their mileage towards the end of a race. 

How Teams Monitor Fuel Mileage:

• Weight Measurement: Opens in new tabTeams weigh the fuel cell and fuel cans before and after refueling to calculate fuel added. 
• Fuel Density: Opens in new tabThey also measure the fuel density to accurately determine the volume of fuel added to the cell. 
• In-Car Data: Opens in new tabModern NASCAR cars use a range of data points to help drivers manage fuel consumption and adjust their driving style accordingly. 

Key Takeaway:
While a passenger car might prioritize fuel economy, a NASCAR engine is designed for power and speed. Therefore, a ~5 mpg efficiency, a highly strategic number for racing, is a different kind of efficiency than what is seen in typical road vehicles.