23 MPG combined isn’t amazing, but it probably won’t deter someone considering the 2015 Infiniti Q50 3.7. This is a sport sedan, and buyers often prioritize performance and a degree of luxury over ultimate fuel efficiency. They want a rewarding driving experience, and they’re willing to accept decent fuel economy to get it.

City and highway performance

The EPA estimates for the 2015 Infiniti Q50 3.7L with the automatic transmission are 20 MPG in the city and 29 MPG on the highway. The city number reflects the inherent inefficiency of stop-and-go driving, where frequent acceleration and braking hurt fuel consumption. The highway number, while decent, isn’t class-leading, indicating that the Q50’s 3.7-liter V6 is working a bit harder at cruising speeds than some of its turbocharged competitors. The seven-speed automatic transmission, while generally smooth, may not be as optimized for fuel efficiency as the eight- or nine-speed units in some newer rivals.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for the 2015 Infiniti Q50 3.7 is $2,500. This figure is based on driving 15,000 miles per year, with 55% of those miles driven in the city and 45% on the highway. The calculation also assumes a national average fuel price, which changes. Your individual fuel costs will vary depending on your driving habits, the type of fuel you use (premium is recommended but not required), and local fuel prices. This $2,500 figure provides a standardized benchmark for comparing the Q50’s fuel costs with other vehicles.

Real-world expectations

EPA estimates provide a useful baseline, but your actual fuel economy in the 2015 Infiniti Q50 3.7L may differ. Some owners report figures slightly below the EPA’s estimates, particularly in city driving where heavy traffic and aggressive driving styles can significantly impact fuel consumption. On longer highway trips, it is possible to match or even slightly exceed the 29 MPG estimate, especially when using cruise control and driving at a consistent speed. However, regularly using the engine’s performance will lead to lower MPG figures.

How it compares

The 2015 Infiniti Q50 3.7’s fuel economy is in the lower-middle of its class. The BMW 328i (2012-2016 with the N20 engine), for example, achieved an EPA-estimated 24 MPG combined, a slight improvement. The Mercedes-Benz C300 from the same era typically manages around 25 MPG combined, thanks to its turbocharged four-cylinder engines. Even the Lexus IS 350, with its naturally aspirated V6, often matches or slightly exceeds the Q50’s mileage. These differences, while seemingly small, can add up over a year. Someone mainly interested in fuel efficiency within this segment may look instead at a Q50 Hybrid; see all Infiniti fuel economy data here.

Tips to maximize efficiency

One of the simplest ways to improve fuel economy in the Q50 3.7 is to adopt a smoother driving style. Avoid rapid acceleration and hard braking, as these consume more fuel. Anticipate traffic flow and maintain a consistent speed when possible. Use the cruise control on the highway to regulate speed and minimize unnecessary throttle adjustments.

Properly maintaining your Q50 can also improve fuel economy. Ensure that your tires are properly inflated to the recommended pressure, as underinflated tires increase rolling resistance and reduce MPG. Regularly scheduled maintenance like oil changes and air filter replacements can contribute to better fuel efficiency. Fouled spark plugs can also reduce MPG.

Reduce unnecessary weight in your vehicle; carrying extra weight in the trunk or passenger compartment puts additional strain on the engine, which lowers fuel economy. Remove any items you don’t need to carry regularly.

Consider using a fuel additive designed to clean fuel injectors and combustion chambers. Over time, deposits can build up in these areas, reducing engine efficiency. Periodically using a fuel additive can help keep your engine running smoothly and maximize fuel economy. Finally, if you are considering other model years, explore the Q50 MPG across all years.