18 MPG combined isn’t going to win any awards, but for the 2018 Infiniti Q70 AWD with the 5.6L V8, it’s what you get for being in a rather specific club. This isn’t a hybrid-electric fuel sipper aiming for maximum efficiency; it’s a luxury sedan delivering a potent blend of performance and comfort. Its buyers aren’t prioritizing thriftiness above all else, but rather seeking a refined driving experience with the reassurance of all-wheel drive grip and the satisfying rumble of a naturally aspirated V8.

City and highway performance

The EPA estimates the 2018 Infiniti Q70 AWD 5.6L at 16 MPG in the city and 23 MPG on the highway. These figures reflect the engine’s inherent characteristics. City driving, with its stop-and-go nature, puts a greater load on the engine, requiring more fuel to get the heavy sedan moving from a standstill.

The highway MPG, while still not especially high, benefits from the engine operating at a more consistent speed, allowing it to achieve slightly better efficiency. The automatic (S7) transmission’s seven gears certainly help optimize power delivery, but ultimately, a large-displacement V8 isn’t going to deliver hybrid-like consumption.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2018 Infiniti Q70 AWD 5.6L to be $3,200. This calculation assumes 15,000 miles driven per year, using the national average fuel price at the time of calculation.

It’s important to remember that this is just an estimate; individual fuel costs will fluctuate depending on driving habits, local fuel prices, and the actual number of miles driven annually. Someone driving predominantly in the city and with a heavy foot will likely far exceed that $3,200 mark, while someone who primarily cruises on the highway with a more gentle approach could potentially come in a bit lower. But $3,200 is a reasonable starting point for budgeting purposes, and starkly differentiates it from vehicles seeking better economy, so see all Infiniti fuel economy data.

Real-world expectations

Real-world MPG for the 2018 Infiniti Q70 AWD 5.6L typically mirrors the EPA’s estimates, but with some variance. Aggressive driving, frequent short trips, and prolonged idling can all significantly decrease fuel economy. Conversely, gentle acceleration, consistent speeds on the highway, and proper tire inflation can help drivers more closely achieve the EPA’s numbers.

Don’t be surprised if city MPG dips into the low teens under heavy traffic conditions. The engine is powerful and responsive, often tempting drivers to indulge in spirited acceleration, which inevitably affects fuel consumption. Use the car’s eco-driving indicator to help adjust your driving style to promote fuel efficiency. Check Q70 MPG across all years to see how different engines compare.

How it compares

Compared to its competitors, the 2018 Infiniti Q70 AWD 5.6L sits squarely in the lower end of the fuel economy spectrum. For example, the Lexus GS 350 AWD achieves around 22 MPG combined, a noticeable improvement.

The BMW 540i xDrive, with its turbocharged inline-six, manages around 24 MPG combined, while still offering similar levels of performance. Even a Mercedes-Benz E450 4MATIC can return around 23 MPG combined. The appeal of the Q70, however, lies in its naturally aspirated V8, a powertrain configuration that provides a different character and feel than the turbocharged alternatives in the BMW and Mercedes. For some buyers, that visceral experience is worth the trade-off in fuel economy. It’s all about priorities. Remember that the Q70 also offers a more sensible 3.7L V6 engine as an alternative with improved MPG.

Tips to maximize efficiency

Avoid aggressive acceleration. The Q70’s V8 is responsive, but each burst of power consumes a significant amount of fuel. Smooth and gradual acceleration will help maximize efficiency, especially in city driving.

Use cruise control on the highway to maintain a consistent speed. Not only does this reduce driver fatigue, but it also helps optimize fuel consumption by preventing unnecessary speed fluctuations.

Keep your tires properly inflated. Under-inflated tires increase rolling resistance, which forces the engine to work harder and consumes more fuel. Check your tire pressure regularly and inflate them to the recommended level, as indicated on the sticker inside the driver’s side door.

Minimize idling. Letting the engine idle for extended periods wastes fuel. If you’re going to be stopped for more than a minute, turn off the engine. Modern engines start up quickly and efficiently, so restarting the engine won’t cause any significant wear or tear.

Use the Infiniti Drive Mode Selector. While this vehicle predates widespread hybrid systems, using “Standard” mode will usually give the best balance of response and efficiency versus using “Sport,” and “Eco” mode will promote fuel economy.