Do all NASCARs use the same engine?

No. NASCAR’s top series run under tightly controlled rulebooks, but they do not all use the same engine. In the Cup Series, Chevrolet, Ford, and Toyota supply different V8s built to common specifications; the Xfinity Series allows both “open” (manufacturer-style) and lower-cost spec options; and the Craftsman Truck Series predominantly uses a single spec engine. Below is how that works in practice in 2025 and why NASCAR structures it this way.

How NASCAR standardizes engines—and where it doesn’t

NASCAR writes detailed engine rules to keep power, reliability, and costs in check, then lets manufacturers and approved builders compete within those limits. In the Cup Series, that means brand-specific engines engineered to the same displacement, architecture, and performance targets. In development series, NASCAR increasingly relies on spec engines to reduce expenses and improve parity, while still allowing some choice when feasible.

Engines by NASCAR national series (2025)

The following rundown explains what each major NASCAR series runs today and how “same” or “spec” the engines really are.

• Cup Series: Teams use manufacturer-specific 358 cu in (roughly 5.9 L) naturally aspirated, pushrod V8s with electronic fuel injection, supplied by Chevrolet (ECR’s R07), Ford (Roush Yates’ FR9), and Toyota (TRD’s V8). They’re built to the same ruleset and power targets—about 670 hp on most tracks and roughly 510 hp at superspeedways via intake restrictions—but they are not identical engines.
• Xfinity Series: Cars run 358 cu in pushrod V8s. Teams can choose between “open” OEM-style engines from approved builders and a NASCAR-approved spec engine option designed to cut costs. Both paths are balanced by rules so neither has a decisive advantage, which means there is no single mandated engine across the field.
• Craftsman Truck Series: The series is centered on a spec engine—the Ilmor 396—used by the vast majority of teams. Legacy/open engines are technically permitted under certain conditions, but they are rarely used given the cost and parity benefits of the spec package.
• ARCA Menards Series (NASCAR-sanctioned ladder): Most teams run the Ilmor NT1 spec engine; older open engines are still allowed with competitive balancing. ARCA serves as a cost-controlled development step.
• Regional/weekly NASCAR divisions (e.g., Whelen Modified Tour, Late Models): Engine rules vary by division, often blending “built” small-block V8s and widely available crate engines (such as Chevrolet 604 or Ford D347SR), with local rulebooks determining what’s legal and how power is balanced.

In short, NASCAR blends strict specifications with limited engineering freedom at the top level, and leans on spec engines in developmental and regional series to keep costs predictable and competition tight.

Why NASCAR doesn’t make every car run the exact same engine

Several policy and competitive goals explain the mixed approach of manufacturer engines in Cup and spec engines elsewhere.

1. Manufacturer identity and relevance: In the Cup Series, Chevrolet, Ford, and Toyota invest heavily in engines because brand competition matters to fans, sponsors, and the companies’ motorsports programs.
2. Cost control in feeder series: Spec engines in Trucks and ARCA dramatically reduce development and maintenance bills, helping smaller teams survive and compete.
3. Parity and show quality: Common rules (and, where used, spec engines) tighten performance windows so driver skill, strategy, and team execution decide more races.
4. Technical oversight: Standardized components—such as the ECU, intake restrictors/spacers, and inspection procedures—let NASCAR police performance, reliability, and safety across different engine suppliers.

Together, these factors allow NASCAR to balance manufacturer competition at the top with sustainable, equitable racing in the ranks below.

What most NASCAR engines still have in common

Despite the differences, NASCAR engines share several core traits intended to preserve the sport’s identity and manage performance.

• Architecture: Naturally aspirated, pushrod V8s with two valves per cylinder remain the standard across the national series.
• Fuel and electronics: A common fuel supplier and a standardized electronic control unit help NASCAR monitor and equalize performance.
• Rule-managed power: Tapered spacers or similar intake restrictions, compression limits, and inspection protocols target specific horsepower ranges by track type.
• Reliability focus: Sealed or tightly regulated components reduce costs and discourage exotic, fragile builds.

These commonalities ensure familiar sound, feel, and race strategy—even as the exact engine suppliers and specs differ by series.

Summary

No, all NASCARs do not use the same engine. Cup cars run manufacturer-specific V8s within a strict rulebook; Xfinity mixes open and spec options; Trucks largely rely on an Ilmor-built spec engine; and ARCA and regional series use spec or crate-based packages to cut costs. NASCAR’s approach preserves brand identity at the top while promoting affordability and parity throughout the ladder.

What engines do Chevy Nascars use?

Chevrolet’s current NASCAR engine is the R07, a 358 cubic-inch (5.8-liter) V8 with a pushrod valvetrain and two valves per cylinder, built by Hendrick Motorsports and ECR Engines. This naturally aspirated, liquid-cooled engine is a bespoke racing design, not a production engine, and can produce over 850 horsepower when unrestricted. It features a compacted-graphite-iron block and is a descendant of the iconic small-block Chevy design, with internal cooling passages and a dry-sump lubrication system.
 
Key Specifications & Features 

• Engine Type: 358 cubic-inch (5.8-liter) V8
• Valvetrain: Pushrod-actuated two-valves per cylinder
• Block Material: Compacted-graphite-iron
• Cooling System: Internally integrated coolant and oil passages
• Lubrication System: Dry-sump system that holds six gallons of oil
• Fuel Delivery: Holley EFI throttle body

Development & Purpose

• The R07 was introduced in 2007 and has been refined in collaboration with NASCAR teams like Hendrick Motorsports and Richard Childress Racing. 
• Its architecture maintains the basic small-block Chevy design, but with advanced materials, tighter tolerances, and improved surface finishes for higher performance. 
• It is a true racing engine, with internal components designed for high RPMs (around 9300-9600 RPM) and high horsepower output. 

This video shows how a NASCAR engine is built: 1mStay TunedYouTube · Mar 29, 2024
Performance

• While capable of revving to 10,000 RPM, the engine’s RPM is limited on the track. 
• In unrestricted trim, the R07 is known to produce over 850 horsepower, with continuous effort from engine builders like ECR to find even minor gains. 

You can watch this video to see a NASCAR engine swapped into a street car: 58sStay TunedYouTube · Aug 24, 2024

What engine is Toyota using in NASCAR?

Toyota NASCAR engines are purpose-built TRD (Toyota Racing Development) 5.9-liter, 358-cubic-inch pushrod V8s, designed for their Xfinity Series and Cup Series stock cars. These naturally aspirated V8s, built by Joe Gibbs Racing in the Xfinity Series and TRD in the Cup Series, produce around 650-700 horsepower in their standard configurations.
 
Engine Type and Performance 

• Engine Type: TRD V8 (pushrod, overhead valve engine)
• Displacement: 5.9 liters (358 cubic inches)
• Horsepower: Approximately 650-700 hp, depending on the series and restriction package.
• Aspiration: Naturally aspirated
• Fuel Delivery: Carburetor

Development and Manufacturing

• TRD: Toyota Racing Development (TRD) designs and builds the engines for Toyota’s NASCAR Cup Series cars. 
• Joe Gibbs Racing: Joe Gibbs Racing (JGR) builds the engines for Toyota’s Xfinity Series cars. 
• Secrecy: TRD maintains high secrecy surrounding its engine designs and development, which helps give their cars a competitive edge. 

Comparison to Production Engines

• Purpose-Built: Unlike older engines based on production models, NASCAR engines are entirely purpose-built racing engines, not modified street car engines. 
• Performance: They are designed to maximize power without mufflers or catalytic converters, allowing for higher output compared to street-legal engines. 

Why is Dodge not allowed in NASCAR?

Ultimately, Dodge chose to withdraw from NASCAR, citing the inability to secure a partnership with a team that met its high standards for competitiveness and technological innovation.

What engine was banned from NASCAR?

NASCAR has banned several engines throughout its history, but two prominent examples are the Ford 427 SOHC Cammer due to its advanced single overhead camshaft design, and the Chrysler 426 Hemi because of its overwhelming dominance, which led to fears of uncompetitiveness. Additionally, the engine in the 1969 Chevrolet Corvette Grand Sport was also banned, not due to rule-breaking, but because GM corporate policy prohibited its factory entry into the competition.
 
The Ford 427 SOHC Cammer

• What it was: A high-performance V8 engine with single overhead camshafts (SOHC) and electronic fuel injection, designed to compete with Chrysler’s Hemi. 
• Why it was banned: NASCAR banned overhead camshaft (OHC) engines, making the Cammer ineligible for stock car competition. 
• Aftermath: Ford shifted its focus to drag racing, where the engine became a legendary and dominant force. 

This video explains why the Ford 427 SOHC Cammer was banned from NASCAR: 38sRare Car StorysYouTube · Feb 12, 2025
The Chrysler 426 Hemi 

• What it was: An incredibly powerful and compact engine that quickly achieved a high level of success in NASCAR. 
• Why it was banned: The Hemi’s dominant performance was so overwhelming that it was banned to “level the playing field” and restore unpredictability to races. 
• Aftermath: The ban wasn’t permanent, and the Hemi was allowed back into NASCAR after rules were revised to ensure its availability in production cars. 

You can watch this video to learn about the history of Hemi engines in NASCAR: 55s4 Wheels ChroniclesYouTube · Sep 23, 2023
Other Notable Banned Engines 

• Smokey Yunick’s “Mystery Motor”: This advanced Chevrolet engine was banned by NASCAR before it ever raced, though not for breaking rules but due to the potential for it to completely rewrite the sport’s history.