What kind of engines do NASCARs use?

NASCAR Cup Series cars use naturally aspirated 358‑cubic‑inch (5.86‑liter) pushrod V8 engines producing roughly 510–670 horsepower, built by Chevrolet, Ford, and Toyota under tightly controlled rules. These engines are bespoke, iron‑block, two‑valve V8s with electronic fuel injection and dry‑sump lubrication, designed for durability at sustained high RPM while preserving close competition through standardized regulations.

The core formula in the NASCAR Cup Series

At the top level, NASCAR’s “Next Gen” Cup cars retain a traditional American V8 architecture: a 90‑degree, single cam-in-block (OHV) pushrod layout with two valves per cylinder and no turbo- or supercharging. Since 2012, Cup engines have used electronic fuel injection rather than carburetors, and they run on Sunoco Green E15 (unleaded gasoline blended with 15% ethanol). Blocks are cast iron for strength, with aluminum cylinder heads for performance and weight savings. In race trim, teams typically target engine speeds near 9,000 rpm, balancing outright power with reliability across long green-flag runs.

How NASCAR controls power

To keep speeds and parity in check, NASCAR mandates a tapered spacer on the intake, limiting airflow and effectively capping horsepower. The sanctioning body sets different packages by track type: approximately 670 hp is used on most ovals and road courses, while superspeedways such as Daytona and Talladega (and the reconfigured Atlanta) run closer to 510 hp. Electronic aids such as traction control remain prohibited; a standardized engine control unit ensures rule compliance without adding driver-assist systems.

The list below summarizes the defining technical traits of modern NASCAR Cup engines.

• Displacement: 358 cu in (5.86 L)
• Configuration: 90° OHV pushrod V8, two valves per cylinder
• Induction: Naturally aspirated with a mandated tapered spacer
• Fuel system: Holley electronic fuel injection with a single throttle body; standardized McLaren ECU
• Fuel: Sunoco Green E15 (15% ethanol)
• Materials: Cast-iron block, aluminum cylinder heads
• Lubrication: Dry-sump system
• Output: About 670 hp on most tracks; about 510 hp at Daytona, Talladega, and Atlanta per rules
• Operating range: Sustained high-RPM operation around 9,000 rpm in race trim

Together, these specifications produce engines that are brutally durable, highly responsive, and closely matched across manufacturers, preserving the drafting and pack racing that define NASCAR competition.

Manufacturers and engine programs

Three automakers participate at the Cup level, each fielding a purpose-built racing V8 that fits the common 358‑cu‑in rulebook while pursuing its own internal designs. Though branded to showroom models, these are not production-based engines; they are clean-sheet racing platforms engineered for reliability, serviceability, and sustained peak output.

Below are the current engine families used in the NASCAR Cup Series and the programs that support them.

• Chevrolet R07-series V8 — Developed by GM; built and prepared primarily by ECR Engines and Hendrick Motorsports.
• Ford FR9 V8 — Developed by Ford Performance; built by Roush Yates Engines.
• Toyota TRD V8 — Developed by Toyota Racing Development; built at TRD’s U.S. engine facilities.

All three meet the same displacement, airflow, and fuel rules; the differences lie in proprietary internals, combustion design, and development strategies that teams guard closely.

What about Xfinity and Craftsman Truck?

NASCAR’s national series all lean on sturdy pushrod V8s, but the exact hardware varies to balance cost, parity, and performance. The Xfinity Series runs engines similar in concept to Cup (naturally aspirated, pushrod 358‑cu‑in V8s) with series-specific rules that typically yield slightly different power and durability targets. The Craftsman Truck Series, by contrast, largely uses a cost-controlled spec engine.

This quick comparison outlines the high-level differences by series.

• Cup Series: Bespoke 358‑cu‑in OHV V8s from Chevrolet, Ford, and Toyota with EFI; about 510–670 hp depending on the track package.
• Xfinity Series: Naturally aspirated 358‑cu‑in OHV V8s built to that series’ rules, delivering comparable but series-adjusted output and longevity targets.
• Craftsman Truck Series: Predominantly the Ilmor NT1, a sealed, cost-contained spec pushrod V8 (approximately 6.0 L) with electronic fuel injection, designed to equalize performance and reduce expenses.

While the specifics differ, each series emphasizes robust, serviceable V8 powerplants that withstand demanding race distances and tight competition.

Why NASCAR sticks with pushrod V8s

The formula balances spectacle, parity, and cost. Pushrod V8s deliver the signature sound and throttle response fans expect, while their mechanical simplicity and proven durability help contain costs for teams. Strict rules keep top speeds in check without resorting to complex hybrid systems or forced induction, preserving the drafting dynamics central to NASCAR’s identity.

Future outlook

NASCAR continues to evaluate technologies that could improve sustainability and relevance—ranging from expanded use of renewable fuels to potential hybrid assistance in the longer term. As of the latest seasons, though, no hybrid systems are used in competition at the Cup level, and the naturally aspirated 358‑cu‑in V8 remains the standard.

Summary

NASCAR Cup cars run bespoke, naturally aspirated 358‑cu‑in pushrod V8s with EFI, making roughly 510–670 hp depending on track rules. Chevrolet, Ford, and Toyota each field their own engines within a tightly regulated framework that emphasizes durability, parity, and the classic NASCAR driving experience. Xfinity uses similar architecture under its own rule set, while the Truck Series relies largely on the Ilmor NT1 spec V8 to control costs and equalize performance.