The 2015 Infiniti Q40 won’t be winning any awards for great gas mileage with its 22 MPG combined. However, it will deliver respectable mileage alongside a charismatic 3.7-liter V6 that was, and arguably still is, one of the best engines in its class. The Q40 isn’t about chasing Prius-level efficiency; it’s about providing spirited performance and luxury at a reasonable price. Buyers of this car understood this trade-off, prioritizing the engine’s responsiveness over great fuel economy. They wanted an engaging driving experience in a well-equipped sedan, and were willing to compromise slightly on MPG to get it.

City and highway performance

The EPA estimates for the 2015 Infiniti Q40 are 19 MPG in the city and 27 MPG on the highway. The city figure reflects stop-and-go traffic, where the Q40’s large V6 consumes more fuel while idling and accelerating. The highway number is more achievable when cruising at a steady speed. The seven-speed automatic transmission helps, offering a taller overdrive gear for relaxed and relatively economical highway driving. Frequent acceleration to pass other cars will quickly lower the highway MPG. This engine rewards aggressive driving with thrilling acceleration, which lowers fuel efficiency.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2015 Infiniti Q40 is $2,650. This is based on driving 15,000 miles per year and assumes national average fuel prices. Your fuel costs can change depending on driving habits, local fuel prices, and the gasoline grade used. The Q40 doesn’t require premium fuel, but some owners prefer it for optimal performance, which increases their yearly fuel costs. Keep that in mind when checking Q40 MPG across all years.

Real-world expectations

EPA figures offer a baseline, but real-world fuel economy can vary. Aggressive driving, frequent short trips, and heavy city traffic usually lower MPG. On the other hand, careful driving habits and consistent highway cruising can bring the numbers closer to, or even slightly above, the EPA estimates. Many Q40 owners say that achieving the rated 27 MPG on the highway is attainable by driving at a constant speed and avoiding quick acceleration. Expect to see numbers in the low 20s in mixed driving conditions. Drive conservatively to maximize MPG if fuel efficiency is a priority.

How it compares

The 2015 Infiniti Q40 is in the middle of its class for fuel economy. The Acura TLX 2.4L offered around 24 MPG combined, a more fuel-efficient choice for buyers less concerned with power. The BMW 335i, with its turbocharged inline-six, had similar performance to the Q40 and got around 25 MPG combined. And the Lexus IS 350, close in performance and luxury, posted a combined MPG of 22. This means the Q40’s fuel economy is typical for a V6-powered luxury sedan of its time, trading some efficiency for better driving.

Be sure to see all Infiniti fuel economy data to compare against other models in the lineup.

Tips to maximize efficiency

The 3.7L V6 often invites heavy acceleration, but avoiding it is the easiest way to improve fuel economy. Watch the traffic and drive at a steady speed whenever possible. Smooth acceleration and gentle braking will lower fuel consumption.

Make sure your tires have the correct air pressure. Underinflated tires increase rolling resistance, making the engine work harder and burn more fuel. Check your tire pressure regularly, especially when the temperature changes.

Avoid idling. If you’re stopped for more than a minute or two, turn off the engine. Idling uses fuel without going anywhere, severely impacting your MPG, especially in city driving.

Take out unnecessary weight in the vehicle. Excess cargo strains the engine, reducing fuel efficiency. Remove items you don’t regularly need to lighten the load.