12 MPG combined. The 2016 Mercedes-Benz AMG G65 6.0L 12-cyl isn’t winning any awards for fuel efficiency. That figure is irrelevant to the G65’s mission. This is a hand-built, massively powerful, unapologetically ostentatious machine that conquers both Rodeo Drive and the Rubicon Trail. Anyone concerned about fuel cost should probably be shopping for a Prius, not a twin-turbocharged V12-powered fortress.

City and highway performance

The EPA rates the G65 at 11 MPG in the city and 13 MPG on the highway. Those numbers are consistently low, translating to frequent stops at the pump. The G65’s immense weight, brick-like aerodynamics, and prodigious power output work against fuel efficiency. Short trips around town highlight the low city rating, as the engine struggles to move this behemoth from a standstill.

Longer highway runs offer a marginal improvement thanks to the 7-speed automatic transmission, but expect the MPG to drop as soon as you unleash even a fraction of the available 621 horsepower.

Annual fuel cost

According to the EPA, the annual fuel cost for the 2016 Mercedes-Benz AMG G65 is $4,800. This calculation is based on driving 15,000 miles per year, with 55% of those miles driven in the city and 45% on the highway, using the national average fuel price at the time of calculation. Expect that figure to fluctuate significantly based on current gas prices and individual driving habits, given this vehicle’s need for premium fuel.

It also doesn’t account for the eagerness many G65 owners likely exhibit; aggressive acceleration will send that annual cost even higher.

Real-world expectations

Hitting the EPA numbers in real-world driving is unlikely. The G65’s character encourages spirited driving. The intoxicating rush of acceleration provided by the V12 engine is too tempting to resist. Expect to see single-digit MPG figures regularly, especially if your driving routine involves a lot of stop-and-go traffic or off-road excursions. Consider the fuel gauge an approximation, not a precise measurement of remaining range. Frequent fill-ups are part of the G65 ownership experience.

How it compares

The G65 exists in a class of its own, but even within the realm of high-performance SUVs, its fuel economy is poor. A contemporary Range Rover Supercharged, with its 5.0-liter V8, manages around 16 MPG combined. The Cadillac Escalade achieves closer to 17 MPG combined with its 6.2-liter V8, although it’s hardly efficient. All Mercedes Benz fuel economy data illustrates that even within the Mercedes-Benz lineup, few vehicles approach the G65’s level of fuel consumption.

Even the mechanically similar, but less powerful, AMG G63 with its twin-turbo V8, sees marginally better fuel economy. Buyers cross-shopping these vehicles understand some compromise is required, but the G65 buyer specifically chooses performance and exclusivity over fuel efficiency. If you are interested in AMG MPG across all years, explore our database.

Tips to maximize efficiency

Resist the urge to floor the accelerator. The G65’s twin-turbo V12 delivers immense power, but using it often will decimate your fuel economy. Gentle acceleration and anticipating traffic flow can make a small, but noticeable, difference, even in a vehicle this thirsty.

Ensure your tires are properly inflated. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Check your tire pressure regularly and maintain it at the recommended level. Because many G65s will be used off-road, immediately reinflate tires to factory specs after airing down.

Minimize aerodynamic drag. While the G65’s shape is inherently un-aerodynamic, avoid adding unnecessary roof racks or cargo carriers that further increase wind resistance. The less the engine has to fight against the wind, the more efficiently it can operate.

Keep up with scheduled maintenance. A properly maintained engine runs more efficiently. Regular oil changes, air filter replacements, and spark plug maintenance can all contribute to optimizing fuel economy, even in a high-performance vehicle like the G65.