What is the most common type of engine mounted in rear-wheel-drive vehicles?

The most common engine in rear-wheel-drive (RWD) vehicles is a longitudinally mounted inline engine—typically an inline-four (I4), with inline-six (I6) also widely used—because its narrow, front-to-back layout aligns directly with the transmission and driveshaft to the rear axle, simplifying packaging and weight distribution. This arrangement has long been favored in RWD sedans, sports cars, and many SUVs and trucks for its mechanical efficiency and balanced handling.

Why inline engines suit rear-wheel-drive

In RWD layouts, power flows from the engine to a gearbox and along a driveshaft to the rear differential. A longitudinal inline engine sits in line with this path, minimizing complexity, improving space for steering components, and facilitating better front-to-rear weight balance—key for predictable handling and traction under acceleration.

Longitudinal vs. transverse mounting

Front-wheel-drive vehicles usually mount engines transversely to save space and integrate the transaxle. In contrast, RWD platforms overwhelmingly use longitudinal mounting, which suits inline engines especially well. While V-type engines are also common in RWD—particularly where higher displacement or lower hood height is desired—the inline format remains the staple for mainstream and enthusiast-focused RWD models.

Common cylinder configurations in RWD

The following list outlines the cylinder layouts most frequently found in RWD platforms and where you’re likely to see each in the market today.

• Inline-four (I4): The most common globally in RWD for its simplicity, compact width, efficiency, and cost-effectiveness; typical in lightweight sports cars and many sedans (e.g., Mazda MX-5, base-model BMW 3 Series).
• Inline-six (I6): Popular in performance and premium segments for smoothness and balanced firing order; seeing a modern resurgence (e.g., BMW B58, Mercedes M256, Stellantis Hurricane I6, Toyota/BMW co-developed platforms).
• V6 and V8: Common in trucks, SUVs, and muscle cars where higher output or packaging under a lower hood is advantageous (e.g., Ford F-150 V6, GM small-block V8s, Dodge/Chrysler HEMI applications).
• Flat (boxer) engines: Rare in RWD front-engine layouts; more often associated with rear- or mid-engine sports cars or specific brands (e.g., Porsche), though Subaru traditionally pairs boxers with AWD.

While V-type and flat engines occupy important niches—especially for power-dense or specialty applications—the inline-four remains the dominant choice for everyday RWD cars, with the inline-six a hallmark of premium and performance-oriented models.

Advantages of longitudinal inline engines in RWD

Automakers favor longitudinal inline engines in RWD platforms for several practical reasons, spanning engineering, handling, and serviceability benefits.

• Straight powerpath: Engine, transmission, and driveshaft align in one axis, reducing drivetrain angles and losses.
• Steering and suspension clearance: Narrow engine width frees space for larger steering angles and suspension geometry.
• Weight distribution: Easier to push mass rearward (front-midship placement), improving balance and traction.
• Modularity: Simplifies mixing different transmissions, transfer cases, and differentials across a platform family.
• Service access: Often better access along the sides of the engine for maintenance in longitudinal bays.

Taken together, these factors explain why longitudinal inline engines remain a default for many RWD architectures, from compact sports cars to executive sedans.

Exceptions and current trends

There are notable exceptions driven by performance targets, packaging constraints, and emissions strategy. V6 and V8 engines remain prevalent in body-on-frame trucks and American performance cars where torque and towing are priorities. Meanwhile, the inline-six is undergoing a modern revival thanks to turbocharging efficiency and smoothness, with manufacturers like BMW, Mercedes-Benz, and Stellantis investing heavily in new I6 families. At the same time, electrification is altering the landscape: many new RWD electric vehicles use rear-mounted drive units, bypassing traditional engine layout considerations altogether.

Summary

The most common engine used in rear-wheel-drive vehicles is a longitudinally mounted inline engine—most often an inline-four, with inline-six also prominent—because it aligns naturally with the RWD drivetrain, optimizes packaging, and supports balanced handling. V6 and V8 engines are widespread in high-output and truck applications, but the inline format remains the backbone of conventional RWD design.

What is the most common type of engine?

The most common engine type is the internal combustion gasoline engine, with the inline four-cylinder configuration being the most prevalent on roads today. This compact and efficient design is found in the majority of commuter vehicles and small cars, prioritizing fuel economy and lower manufacturing costs.
 
Why the Inline Four is so Common

• Simplicity and Cost: The inline engine’s design is straightforward, allowing for simpler and cheaper manufacturing. 
• Compact Size: Its compact nature makes it ideal for smaller vehicles, saving space and allowing for more efficient packaging in the engine bay. 
• Efficiency: The inline four-cylinder engine offers a good balance between power output and fuel efficiency, making it a popular choice for everyday driving and commuter vehicles. 
• Market Presence: A significant percentage of vehicles on the road are powered by four-cylinder engines, with this configuration holding a high market share for new vehicle sales. 

Other Engine Types
While the inline four-cylinder is the most common, other popular engine types include: 

• V-type engines: Opens in new tabThese engines have cylinders arranged in a V-shape and are known for their smoothness and ability to provide more power, making them a choice for higher-performance vehicles. 
• Inline-six engines: Opens in new tabThese offer a smoother experience than inline-fours and are found in some mid-size and luxury cars. 
• Hybrid and Electric Engines: Opens in new tabThese represent a growing category of engine types that are becoming increasingly common. 

What is the most common type of engine installation in a rear-wheel drive vehicle is a rear mid mount transverse longitudinal?

Option D, “longitudinal,” means the engine is installed front-to-back. This is the most common configuration for rear-wheel-drive vehicles, as it allows for a direct connection to the rear axle and is often used in sedans, SUVs, and trucks.

Where is the engine mounted in a rear-wheel drive car?

In automotive design, an RR, or rear-engine, rear-wheel-drive layout places both the engine and drive wheels at the rear of the vehicle. In contrast to the RMR layout, the center of mass of the engine is between the rear axle and the rear bumper.

What is the most common type of engine mounted in rear-wheel drive vehicles?

The most common engine configuration in rear-wheel drive vehicles is a longitudinally mounted engine located at the front of the vehicle. This arrangement, where the engine’s crankshaft runs parallel to the vehicle’s length, allows for a direct and efficient transfer of power via a driveshaft to the rear wheels. 
Here’s why this is common:

• Simplicity: A longitudinal engine placement creates a straightforward powertrain with components largely separated, simplifying the design and assembly process. 
• Power Transfer: The longitudinal orientation naturally aligns the engine with the drivetrain, providing a direct path for the driveshaft to spin and deliver power to the rear differential and wheels. 
• Weight Distribution: While not the most balanced, placing the engine at the front provides a relatively stable and manageable weight distribution for everyday vehicles like sedans, SUVs, and trucks. 

While less common, other configurations exist for specific performance or packaging benefits: 

• Transaxle Layouts: Opens in new tabSome RWD cars, like the Porsche 944 or older Corvettes, have the engine at the front and the transmission and differential combined into a single unit (a transaxle) at the rear for better weight balance. 
• Mid-Engine Layouts: Opens in new tabHigh-performance sports cars often use a mid-engine, rear-wheel-drive setup, placing the engine behind the passenger compartment but in front of the rear axle for optimal handling and weight distribution. 
• Rear-Engine Layouts: Opens in new tabVehicles like the Volkswagen Beetle and the classic Porsche 911 used a rear-engine, rear-wheel-drive layout, with a transaxle driving the rear wheels.