21 MPG combined is what you get with the 2025 Cadillac CT5 V, equipped with the 3.0L twin-turbo V6. It’s not a fuel sipper, and it wasn’t designed to be. This is a driver’s sedan that focuses on performance and luxury rather than outright economy. Buyers in this segment know what they’re getting into, accepting a slightly higher fuel bill for the engaging experience the CT5 V provides. They want a car that makes a statement, both visually and dynamically.

City and highway performance

The EPA estimates the CT5 V gets 18 MPG in the city and 27 MPG on the highway. The city figure shows the strain on the engine during stop-and-go traffic, where the twin turbos frequently spool up. The highway number shows the engine’s ability to cruise efficiently at steady speeds, thanks to the smooth-shifting 10-speed automatic transmission (S10). The highway number will likely drop if you frequently engage the car’s performance-oriented driving modes and its horsepower for passing.

Annual fuel cost

According to the EPA, the 2025 Cadillac CT5 V with the 3.0L V6 has an estimated annual fuel cost of $2,750. This is based on driving 15,000 miles per year and using national average fuel prices. This is just an estimate; your actual fuel costs may vary depending on your driving habits, local fuel prices, and how often you drive the CT5 V hard.

Real-world expectations

The EPA estimates provide a baseline, but real-world fuel economy often differs. CT5 V owners who frequently drive aggressively, live in areas with heavy traffic, or drive mostly in the city will likely see numbers below the EPA’s 21 MPG combined rating.

However, those who primarily drive on the highway and drive more conservatively might achieve figures closer to, or even slightly above, 27 MPG on the open road. Driving style really impacts mileage in this vehicle and others.

How it compares

In the world of performance-oriented luxury sedans, the CT5 V’s fuel economy is somewhere in the middle. The BMW M340i, with its turbocharged inline-six, gets a slightly better 26 MPG combined, while the Mercedes-AMG C43 gets around 21 MPG combined, similar to the CT5 V. The Audi S4 gets around 24 MPG combined, demonstrating the competition. Buyers cross-shopping these vehicles shouldn’t expect major differences in fuel costs, as performance and luxury are the main reasons to buy.

Many buyers might also be interested in reviewing CT5 MPG across all years.

Tips to maximize efficiency

Use the CT5 V’s driving mode selector. Selecting “Tour” mode relaxes the throttle response and optimizes the transmission for fuel efficiency, making it ideal for everyday driving. It’s tempting, but try to resist constantly using the more aggressive “Sport” or “Track” modes, as these prioritize performance.

Make sure your tires are properly inflated. Underinflated tires increase rolling resistance, forcing the engine to work harder. Check your tire pressure regularly and inflate them to the manufacturer’s recommended levels, which are on the sticker on the driver’s side door jamb.

Avoid aggressive acceleration and hard braking. Smooth and gradual acceleration helps maximize fuel efficiency. Anticipate traffic flow and avoid unnecessary braking by gently coasting to a stop when you can. The twin-turbo engine is responsive, but being gentle with the throttle can save you money.

Consider using cruise control on the highway. Maintaining a constant speed with cruise control minimizes unnecessary acceleration and deceleration, helping to improve fuel economy on long drives. Keep your eyes on the road and adjust your speed to keep a safe distance.

Minimize idling time. Letting the engine idle for a long time uses fuel. If you expect to be stopped for more than a minute, turn off the engine. Modern vehicles like the CT5 V restart quickly, so there’s no need to let it run. Buyers can explore all Cadillac fuel economy data to see how the CT5 V compares.