What is a straight-four (inline-4) engine?

A straight-four, or inline-4, engine is a compact and efficient engine layout where four cylinders are arranged in a straight line. It is widely used in sedans, SUVs, and performance cars because it balances usable power with fuel efficiency.

Why does Honda use inline-four engines?

Honda uses inline-four engines in vehicles like the Civic, Accord, and CR-V because they offer proven reliability, strong efficiency, and performance potential. Honda technologies such as VTEC, turbocharging, and hybrid integration enhance these engines further.

Are inline-four engines powerful enough?

Yes, modern inline-four engines are highly capable. For example, the Honda Civic Type R's 2.0L turbocharged inline-four produces 315 horsepower, while the Accord's 1.5L turbocharged engine delivers 192 horsepower with smooth and dependable acceleration.

How fuel-efficient are inline-four engines?

Inline-four engines are efficient by design. For example, the 2025 Honda CR-V with a 1.5L turbocharged four-cylinder achieves up to 28 mpg city and 34 mpg highway, while hybrid versions offer even better mileage and reduced emissions.

What are the benefits of owning a straight-four engine vehicle?

Straight-four engines provide reliable performance, smooth power delivery, good fuel economy, and lower maintenance costs thanks to their simpler design. These qualities make them a smart choice for daily commuting, long trips, and overall value.

Straight-Four Engine Power: Performance and Efficiency

The straight-four engine, or inline-four, is one of the most widely used engines in the auto industry. It's compact, efficient, and powerful enough for everything from compact sedans to midsize SUVs.

Automakers favor the inline-four engine because it strikes a balance between usable power and everyday fuel efficiency. For Honda, the four-cylinder has been the heart of legacy models like the Civic, Accord, and CR-V, combining proven reliability with advanced technologies such as VTEC, and Hybrid.

Straight-Four Engine Basics

Here's why the straight-four layout has become a standard choice for automakers:

Cylinder arrangement: Four cylinders set in a row, firing in a 1-3-4-2 sequence for smooth operation
Displacement range: Commonly between 1.5 and 2.5 liters, striking a balance between power and efficiency
Compact design: Lightweight and space-saving, freeing room for safety systems, and cabin space
Efficiency-friendly: Fewer moving parts reduce friction and improve fuel economy
Easy to upgrade: Often paired with direct injection, variable valve timing, and turbocharging for increased power output without larger size or weight

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Performance Capabilities of the In-Line Four

Straight-fours may not have the cylinder count of a V6 or V8, but modern engineering has made them responsive and highly capable. Honda's long history with VTEC (Variable Valve Timing and Lift Electronic Control) is a standout example. First introduced in the late 1980s, VTEC enabled engines to run efficiently at low speeds while producing strong power at higher rev ranges, a breakthrough that gave small cars genuine performance credentials.

That legacy carries forward in today's lineup. The Civic Type R uses a 2.0-liter turbocharged inline-four with VTEC, producing 315 horsepower and 310 lb-ft of torque. It shows how far this layout can be pushed while remaining road-ready. For everyday use, the Accord's 1.5-liter turbocharged inline-four delivers 192 horsepower, offering smooth and dependable acceleration. And for those who enjoy a modern classic, Honda's S2000 roadster (1999–2009) featured a 2.0-liter inline-four that revved to 9,000 rpm, cementing its place as one of the most exciting naturally aspirated fours ever built.

Efficiency, Fuel Economy & Power

The straight-four is efficient by design. Fewer cylinders mean less internal friction, lighter weight, and better fuel management. Honda builds on these fundamentals with i-VTEC, turbocharging, and hybrid integration, enabling drivers to enjoy performance without compromising mileage.

For example, the 2025 Honda CR-V, with its 1.5-liter turbocharged four, achieves EPA-estimated 28 mpg city and 34 mpg highway in front-wheel-drive versions. Hybrid trims combine a 2.0-liter inline-four with electric motors, producing 204 horsepower while delivering even higher city mileage and fewer emissions. These results demonstrate the continued importance of the straight-four engine in meeting fuel economy and emissions standards, particularly in high-volume crossovers and sedans.

How the Four Cylinder Benefits Drivers

The appeal of the straight-four goes beyond stats and numbers. Its simplicity and reliability are big reasons why millions of vehicles use this design. With fewer cylinders and parts to manage, service is more straightforward, which helps keep maintenance costs lower over the long term.

The driving experience is another benefit. Straight-fours offer smooth, consistent power delivery that works well for both commuting and highway travel. In Honda's lineup, the Civic, Accord, HR-V, and CR-V all use four-cylinder engines, offering buyers a familiar blend of high performance and economy across varying body styles. Whether tuned for efficiency or performance, the inline-four proves adaptable and dependable.

The Straight Four

The straight-four engine continues its reign because it delivers what most drivers need: reliable performance, good fuel economy, and lower ownership costs. Honda's use of technologies like VTEC, turbocharging, and hybrid pairing shows how this layout continues to evolve while staying practical.

To explore Honda models powered by advanced straight-four engines, visit Mountain View Honda and see how this proven design can fit your driving needs.