17 MPG combined is what you get with the 2020 Cadillac CT6 AWD, equipped with the 4.2L Blackwing V8. Let’s be honest: anyone considering this car probably isn’t prioritizing fuel efficiency. This CT6 is a potent mix of American luxury and serious performance. Owners want the reliable power delivery and distinctive sound of a hand-built, twin-turbocharged V8, and are prepared to accept the related fuel consumption.

City and highway performance

The EPA estimates the CT6 V8 gets 14 MPG in the city and 25 MPG on the highway. The city figure reflects the engine’s thirst during stop-and-go driving, where the turbos are constantly spooling up and down. The highway MPG is better, showing the engine’s ability to cruise efficiently at steady speeds. The 10-speed automatic transmission helps optimize fuel economy on the open road, keeping the engine in its sweet spot.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2020 Cadillac CT6 AWD 4.2L V8 at $3,400. This is based on driving 15,000 miles per year, with 55% of those miles driven in the city and 45% on the highway. It also assumes national average fuel prices. Keep in mind that fluctuating gas prices and your individual driving habits can change this number, likely upwards if you frequently use the CT6’s considerable power.

Real-world expectations

While the EPA figures provide a benchmark, real-world MPG is often lower, especially for drivers who enjoy the CT6’s performance. In mixed driving conditions, expect to see numbers closer to the stated city MPG, particularly if you drive aggressively. Frequent use of the car’s “Sport” mode, which sharpens throttle response and holds gears longer, will also negatively impact fuel economy. Owners who primarily stick to highway driving may be able to match or slightly exceed the EPA’s 25 MPG estimate.

This is an enthusiast vehicle; if you’re constantly checking the MPG readout, you might have picked the wrong car. View CT6 MPG across all years for more performance data.

How it compares

Compared to other performance-oriented luxury sedans, the CT6 V8’s fuel economy is in the expected range. The BMW M5, for example, is rated at 17 MPG combined, the same as the CT6. The Mercedes-AMG E63 S comes in slightly lower at 19 MPG combined, despite advanced features. Even less powerful versions of the CT6 offer better fuel economy; view all Cadillac fuel economy data for a comparison. These comparisons highlight the tradeoff between performance and efficiency in this vehicle class. Buyers are willing to sacrifice MPG for the experience and exclusivity these cars offer, but there are some competitors that offer alternatives.

Tips to maximize efficiency

Avoid aggressive acceleration and hard braking. The CT6 V8’s twin turbos respond quickly to throttle inputs, so smooth acceleration will help minimize fuel consumption. Anticipate traffic flow and maintain a steady speed.

Use the car’s “Tour” driving mode for everyday commuting. This mode softens throttle response and optimizes shift points for fuel efficiency. “Sport” mode is tempting, but save it for spirited driving when fuel economy is less of a concern.

Ensure your tires are properly inflated. Under-inflated tires increase rolling resistance, which reduces fuel economy. Check your tire pressure regularly and inflate them to the recommended levels listed on the driver’s side doorjamb.

Minimize idling time. Letting the engine idle consumes fuel. If you’re stopped for more than a minute, consider turning off the engine.

Keep up with routine maintenance. Regular oil changes, air filter replacements, and spark plug maintenance can help ensure your engine is running efficiently. A well-maintained engine will deliver optimal fuel economy.