14 MPG combined. That’s bad by modern standards. But the 2015 Cadillac CTS 6.2L 8-cyl isn’t trying to save you fuel. It’s about strong, unrestrained American power in a package that offers advanced features. Buyers of this car want a visceral driving experience, a sledgehammer of an engine that gives instant gratification every time they hit the accelerator, and they’re okay with the high gas costs. They aren’t looking at Priuses, and they probably won’t even check the fuel economy on the window sticker.

City and highway performance

The EPA estimates for the CTS-V are 12 MPG in the city and 18 MPG on the highway. In cities, stop-and-go traffic will really hurt your gas mileage. The supercharged V8 drinks fuel, especially if you give in to the temptation to use even a little of its power at every green light. Highway driving gives a little hope, if you can avoid hitting the gas to pass. Even at a constant speed, though, the V8 works hard, and its large size means that any fuel savings are small.

Annual fuel cost

The EPA estimates that the 2015 Cadillac CTS 6.2L 8-cyl will cost $4,150 per year for fuel. This is based on driving 15,000 miles a year, with 45% in the city and 55% on the highway. It also assumes average national gas prices. Since the CTS-V will likely encourage you to drive hard, and gas prices change, think of $4,150 as a minimum. You’ll probably spend more, if you really use the car’s performance.

Real-world expectations

The EPA provides a standard, but your actual mileage will depend on how you drive, traffic, and maintenance. Someone who drives lightly and mostly uses the CTS-V for highway commuting might get close to the EPA’s 18 MPG highway estimate. But most owners will probably see numbers closer to the combined 14 MPG, or even less during fast driving. Regular maintenance, like keeping tires inflated and changing oil on time, can help keep fuel efficiency as high as possible, though the improvement will be small because of the engine.

How it compares

The 2015 CTS-V is near the bottom of the fuel economy list compared to its competition. The BMW M5, a direct competitor with a similar turbocharged V8, gets a combined EPA rating of 17 MPG. The Mercedes-Benz E63 AMG gets about 16 MPG combined. Even the Audi RS7, with its all-wheel-drive adding weight, gets 18 MPG combined. These differences show that the CTS-V focuses on power first. The Dodge Charger Hellcat, also with a supercharged V8, gets 16 MPG combined, similar to the German cars. This comparison is important because the CTS-V buyer probably does market research and knows the trade-offs, even if they don’t care about economy. Find all Cadillac fuel economy data on our site.

Tips to maximize efficiency

Don’t accelerate hard all the time. The supercharged V8 reacts quickly, but every time you floor it, you use a lot of gas. Accelerating smoothly can make a difference over time, even though it’s hard to resist.

Keep a consistent speed on the highway. Cruise control can help minimize changes in the throttle, which improves fuel efficiency. Don’t change lanes or brake suddenly, since these actions need more power and use more gas.

Make sure your tires have enough air. Tires with low pressure increase rolling resistance, which reduces fuel efficiency. Check your tire pressure often and inflate them to the manufacturer’s recommended levels, which you can find on the doorjamb sticker.

Cadillac recommends premium fuel. While the engine can run on regular gasoline, premium fuel can make the car perform better and may slightly improve fuel efficiency. Check your owner’s manual for advice. Explore CTS MPG across all years.

Don’t let the car idle. If you’re stopped for more than a minute, turn off the engine. Idling uses fuel without moving the car, so avoid it, especially in stop-and-go traffic. This is especially true for the CTS-V because of its big engine.