32 MPG combined is respectable, but it’s also beside the point for the 2018 Honda Civic Si 4Dr. This isn’t a Prius, and nobody buys an Si chasing ultimate fuel efficiency. This car is for enthusiasts who prioritize engagement and fun, and its fuel economy is simply a reasonable byproduct of a well-engineered, turbocharged engine paired with a slick-shifting six-speed manual.

City and highway performance

The EPA estimates 28 MPG in the city and 38 MPG on the highway for this Civic Si. The highway figure is particularly impressive, demonstrating the engine’s efficiency when cruising at steady speeds. The city MPG reflects the reality of stop-and-go traffic and the more aggressive driving style that the Si tends to encourage.

The 1.5-liter turbocharged engine provides a broad torque curve, making it responsive across the rev range, which contributes to both enjoyable driving and reasonable fuel consumption. However, frequent use of boost (and you will use boost) will invariably lower your MPG.

Annual fuel cost

The EPA estimates an annual fuel cost of $1,800 for the 2018 Honda Civic Si 4Dr. This calculation is based on driving 15,000 miles per year and using the national average fuel price. Keep in mind that fuel prices fluctuate, and your actual fuel cost will vary depending on your driving habits and where you live. The EPA’s estimates provide a standardized way to compare the fuel costs of different vehicles, even if your personal results might differ.

Real-world expectations

While the EPA estimates provide a benchmark, real-world fuel economy often varies. Si owners frequently report MPG figures slightly below the EPA’s estimates, especially in combined driving. A heavy right foot and a love for winding roads can easily drop the average MPG into the high 20s. Conversely, a conscious effort to drive efficiently, focusing on smooth acceleration and maintaining steady speeds, can help achieve or even exceed the EPA’s numbers.

Ultimately, the MPG you achieve will depend on your driving style and the conditions you encounter. For those seeking maximum MPG in a CIVIC MPG across all years, the Si isn’t the ideal choice; other trims prioritize fuel efficiency to a greater extent.

How it compares

Compared to other sporty compact cars of its era, the 2018 Civic Si holds its own. The Volkswagen GTI, a perennial benchmark in the segment, achieves an EPA-estimated 24 MPG combined with its manual transmission. The Subaru WRX, known for its all-wheel-drive performance, manages a lower 21 MPG combined. The Hyundai Elantra Sport, another competitor, comes in at around 29 MPG combined.

The Si isn’t the absolute efficiency champion in this class, however it strikes a balance between performance and fuel economy, one of the reasons why this car has been so popular. If the Si’s mileage doesn’t suit you, you might want to consider all Honda fuel economy data.

Tips to maximize efficiency

Pay attention to tire pressure. Maintaining the correct tire pressure, as indicated on the door jamb sticker, can improve fuel economy by a small but noticeable amount. Underinflated tires increase rolling resistance, requiring the engine to work harder and consume more fuel. Regularly check and adjust your tire pressure to optimize efficiency.

Use cruise control on the highway. Maintaining a consistent speed on the highway can significantly improve fuel economy. Cruise control helps to minimize unnecessary acceleration and deceleration, which wastes fuel. Use cruise control whenever possible on long highway stretches.

Anticipate traffic flow. By looking ahead and anticipating traffic patterns, you can avoid sudden braking and acceleration. This smooth driving style not only improves fuel economy but also enhances safety. Observe the vehicles ahead and adjust your speed accordingly.

Minimize idling. Idling consumes fuel without covering any distance. If you’re stopped for more than a minute, turn off the engine. Modern engines are designed to restart quickly and efficiently, so you won’t cause any undue wear and tear. Avoid idling in drive-throughs or while waiting for someone.

Consider using higher gears when appropriate. The Civic Si’s six-speed manual transmission allows for flexible driving. Shifting into higher gears at lower RPMs can improve fuel economy, especially in city driving. Avoid revving the engine unnecessarily high before shifting, as this wastes fuel.