What kind of engines do NASCARs have?

NASCAR race cars use naturally aspirated 5.86-liter (358 cubic-inch) pushrod V8 engines; in the Cup Series they’re fuel-injected, rev to roughly 9,000 rpm, and make about 670 horsepower at most tracks (reduced to roughly 510 hp at superspeedways), with purpose-built engines from Chevrolet, Ford, and Toyota. Below is a deeper look at the hardware, the rules that shape it, and how the different national series compare.

The core NASCAR Cup Series engine formula

At the top level, the NASCAR Cup Series mandates a traditional American small-block architecture: a 90-degree, cam-in-block (OHV) pushrod V8 with two valves per cylinder and no turbocharging or supercharging. Displacement is capped at 358 cu in (5.86 L). Since 2012, Cup has used electronic fuel injection (EFI) managed by a standardized control unit, and since 2011 the series has run on Sunoco Green E15 (gasoline with 15% ethanol). The engines use dry-sump lubrication, cast-iron blocks with aluminum cylinder heads, and are designed for both parity and durability under long, full-throttle race conditions.

Power, revs, and track-dependent trims

Output is controlled primarily by airflow limiters called tapered spacers. As of the 2025 season, NASCAR targets approximately 670 hp for most oval tracks and road courses, and about 510 hp for superspeedways such as Daytona, Talladega, and the reconfigured Atlanta. Peak engine speed in competition typically resides in the high 8,000s to around 9,000 rpm, depending on gearing and aero drag. Teams tune for throttle response, reliability, and fuel economy within the tight rules package.

Who builds them and what they’re called

Each manufacturer supplies a purpose-built, NASCAR-homologated racing V8. These are not production-block engines; they are clean-sheet racing designs that still conform to NASCAR’s pushrod, two-valve template.

• Chevrolet: R07/R07.2 small-block V8
• Ford: FR9 V8
• Toyota: TRD 5.86L V8

Although the branding is tied to road cars, the internals are bespoke for racing: robust bottom ends, high-flow cylinder heads, and tightly controlled components to hit NASCAR’s parity and reliability goals.

Engines across NASCAR’s national series

While the Cup Series sets the headline formula, the Xfinity and Craftsman Truck Series run closely related but distinct packages tailored to their competitive and cost-control needs.

• Xfinity Series: Also uses 358 cu in pushrod V8s with EFI and tapered spacers. Power is typically in the roughly 600–650 hp range at most tracks, with lower output at superspeedways via more restrictive spacers.
• Craftsman Truck Series: Runs a spec Ilmor “NT1” pushrod V8 (396 cu in/6.5 L) designed for durability and cost containment. Output is generally in the mid-600 hp range and is trimmed down further at superspeedways.

Across all three series, the goals are similar: keep speeds in a safe, competitive window, maintain brand identity, and control costs while preserving the throaty, high-rpm character fans expect.

Key components and technologies

NASCAR’s rules fix the big architectural choices but leave room for optimization in materials, airflow, friction reduction, and calibration. These are the headline elements you’ll find in a modern NASCAR engine bay.

• Induction and fuel: Single-throttle EFI with a standardized ECU; no forced induction; E15 fuel.
• Valvetrain: Single cam-in-block with pushrods and two valves per cylinder; aggressive cam profiles; robust valve springs and lightweight valvetrain parts to survive high rpm.
• Block and heads: Cast-iron blocks for rigidity and cost control; aluminum heads for airflow and weight; dry-sump oiling for reliability under sustained lateral loads.
• Exhaust: Equal-length headers tuned for scavenging and the series’ signature sound.
• Controls and data: Spec electronics for parity; limited sensor suites compared with many international series, emphasizing team craft and reliability.

The combination yields a distinctly American V8 character—big displacement, immediate throttle response, and durability for races that often exceed 500 miles.

Rules that shape how NASCAR engines perform

NASCAR’s technical regulations keep different manufacturers on a tight performance leash, prioritizing close racing and safety over unrestricted power.

• Displacement cap: Maximum 358 cu in (Cup and Xfinity), with tightly controlled bore and stroke windows.
• Airflow limits: Tapered spacers in all three national series to target track-specific horsepower.
• No boost: No turbochargers or superchargers permitted.
• Fuel and ignition: Spec EFI and ECU; Sunoco Green E15 across the national series.
• Durability and cost: Policies encourage multi-race engine life cycles and limit exotic materials.

These constraints create engines that are highly optimized within a narrow box, emphasizing reliability and driver skill rather than sheer power escalation.

How they sound—and why

The cross-plane crankshaft, even firing order, and long-tube headers give NASCAR V8s their thunderous, bass-heavy exhaust note. With high compression, big displacement, and no turbochargers to muffle pulses, the result is a sharp, percussive sound that remains one of the sport’s trademarks.

What’s next: hybrid talk and electrification experiments

As of the 2025 season, NASCAR’s Cup, Xfinity, and Truck races remain purely internal-combustion. NASCAR and its OEMs have, however, explored future propulsion paths. In 2024, NASCAR publicly demonstrated an all-electric prototype developed with its manufacturer partners, signaling research into alternative powertrains and sustainability. While timelines for any hybrid assist or alternative-fuel race package have not been finalized, ongoing development suggests the series is preparing options that could complement the V8 formula in the years ahead without immediately replacing it.

Summary

NASCAR race cars run purpose-built, naturally aspirated pushrod V8s: 358 cu in EFI engines in Cup and Xfinity, and a spec pushrod V8 in Trucks, all tuned with tapered spacers for track-specific power. They’re loud, durable, high-revving, and tightly regulated to deliver close racing while preserving the sport’s signature character. Future developments may add hybrid or alternative-power elements, but the thunderous American V8 remains the heart of NASCAR today.

Do Chevy Nascars use Chevy engines?

The Chevrolet engine in Cup is called a R07. 2. That’s a 5.8L two-valve per cylinder V8. Its roots are in the small block Chevy era from 50-plus years ago.

How many horsepower is the average NASCAR?

The horsepower in a NASCAR Next Gen Cup car averages 670 hp on standard tracks and is reduced to 510 hp on restrictor-plate superspeedways. The horsepower rating can change year-to-year and is adjusted based on track type to ensure driver and spectator safety and to promote closer racing.
 
Horsepower by Track Type: 

• 670 HP (500 kW): Opens in new tabThis is the standard output for most tracks, including road courses and short tracks.
• 510 HP (380 kW): Opens in new tabThis reduced output is used on superspeedways with restrictor plates to manage high speeds and keep the cars from becoming too fast and dangerous.

Why the Horsepower Changes 

• Safety: High-speed tracks can be dangerous, and reducing horsepower keeps the cars from reaching extreme speeds, which could cause debris to fly into the grandstands.
• Race Equality: The use of restrictor plates helps to equalize the speed of the cars, making the competition closer.

History of Horsepower Changes

• Horsepower levels have changed significantly over the years. 
• For instance, the Generation 6 cars in 2019 had varying outputs of 750 hp and 550 hp, with the introduction of the Next Gen car in 2022 leading to the current 670 hp/510 hp configuration. 

What’s faster, Formula 1 or NASCAR?

Formula 1 (F1) cars are significantly faster than NASCAR cars, both in terms of top speed and overall lap times, because F1 cars are lighter, more aerodynamically advanced, and have a higher power-to-weight ratio. F1 cars can reach top speeds over 220 mph and have superior acceleration, allowing them to corner much faster than NASCAR vehicles. 
Key Differences in Speed & Performance

• Top Speed: F1 cars reach higher top speeds than NASCAR cars, with F1s topping out above 220 mph, while NASCARs typically reach around 200 mph. 
• Acceleration: F1 cars have much quicker acceleration, achieving 0-60 mph in about 2.6 seconds compared to NASCAR’s roughly 3.4 seconds. 
• Aerodynamics & Downforce: F1 cars use advanced aerodynamics to generate significant downforce, allowing them to take corners at extremely high speeds. NASCAR’s design prioritizes different aerodynamic principles for overtaking and drafting on ovals. 
• Weight & Power: F1 cars are much lighter and have more powerful engines relative to their weight, giving them a distinct performance advantage over the heavier NASCAR stock cars. 
• Lap Times: Due to their superior acceleration and cornering ability, F1 cars can lap a circuit much faster than a NASCAR car. For example, F1 cars are significantly faster on shared road courses. 

What is special about NASCAR engines?

At its core, a NASCAR race car is powered by an 8-cylinder engine that can produce up to 850 horsepower. This engine relies on high-performance fuel injection systems and sophisticated computer systems to regulate air intake, fuel delivery, and ignition timing for maximum performance on the track.