22 MPG combined. That’s the EPA’s official fuel economy estimate for the 2021 Cadillac CT5 equipped with the 3.0L twin-turbo V6. It’s not winning any awards for less gas. But this car is for drivers who prioritize a balance of performance and luxury over outright efficiency, who want a quick and stylish sport sedan that won’t completely break the bank at the pump. A Prius driver might scoff, but the CT5 3.0T buyer is more likely cross-shopping against a BMW 340i or Audi S4 and is willing to accept mid-20s fuel economy for the satisfying rush of 335 horsepower.

City and highway performance

The EPA breaks down the CT5 3.0T’s fuel economy estimates further, providing individual ratings for city and highway driving. In urban environments, the CT5 3.0T uses fuel at a rate of 19 MPG. This reflects the stop-and-go traffic and lower average speeds that are typical of city driving. The twin-turbo V6 needs extra fuel to get this car moving from a stop, especially when using all available horsepower. On the open road, the CT5 3.0T fares better, achieving 28 MPG in highway driving. The ten-speed automatic transmission helps here, keeping the engine in its most efficient range at cruising speeds. This shows the CT5 is not just a city runabout, but it is also a comfortable long-distance cruiser.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2021 Cadillac CT5 3.0T at $2,650. This figure 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 at the time the EPA testing was conducted. Of course, your actual fuel costs may vary depending on your driving habits, location, and the current price of gasoline. However, $2,650 provides a useful benchmark for comparing the CT5 3.0T’s running costs to those of other vehicles. You can view CT5 MPG across all years to see how it compares with other model years.

Real-world expectations

While the EPA estimates provide a standardized measure of fuel economy, those numbers rarely translate directly into real-world driving. Several factors can influence fuel consumption, including driving style (aggressive acceleration and braking will reduce MPG), traffic conditions (stop-and-go traffic hurts MPG), and even weather conditions (cold weather can decrease fuel economy). Expect to see numbers slightly below the EPA estimates if you frequently drive in heavy traffic or have a lead foot. Conversely, if you primarily drive on the highway at moderate speeds, you may be able to achieve fuel economy that’s closer to, or even slightly above, the EPA’s 28 MPG highway rating.

How it compares

The Cadillac CT5 3.0T exists in a competitive segment, facing rivals that also offer a blend of performance and luxury. The BMW 340i, for example, is rated at 26 MPG combined, making it slightly more fuel-efficient than the CT5. The Audi S4, another popular choice, achieves 24 MPG combined. However, both the BMW and Audi often command a higher price tag than the CT5, making the Cadillac a good value for buyers who want performance without the premium cost. A Lexus IS 350 F Sport, on the other hand, comes in at 23 MPG combined, putting it right in line with the CT5. The comparison matters because buyers in this segment are often willing to trade a small amount of fuel economy for a more engaging driving experience or a better value for their money. They will likely research all Cadillac fuel economy data to see a range of choices.

Tips to maximize efficiency

The most direct way to improve fuel economy in the CT5 3.0T is to adopt a smoother driving style. Avoid rapid acceleration and hard braking, as these actions consume significantly more fuel. Anticipate traffic flow and maintain a steady speed whenever possible. The ten-speed automatic is programmed for efficiency; let it do its job.

Ensure your CT5’s tires are properly inflated. Underinflated tires increase rolling resistance, which reduces fuel economy. Consult the sticker on your driver’s side doorjamb for the recommended tire pressure. Check your tire pressure regularly, especially during seasonal changes.

Minimize the use of accessories such as air conditioning and heated seats, as these draw power from the engine and impact fuel consumption. When possible, open the windows for ventilation instead of running the A/C. Keep in mind that even at highway speeds, keeping the windows up and running the A/C is often more fuel efficient due to aerodynamic drag.

Reduce the weight you’re carrying in the vehicle. Excess cargo adds to the vehicle’s load, forcing the engine to work harder and consume more fuel. Remove any unnecessary items from the trunk or cabin.

Finally, keep up with regular maintenance. A well-maintained engine runs more efficiently. Follow the recommended maintenance schedule in your owner’s manual, including oil changes, air filter replacements, and spark plug replacements. This will ensure that your CT5 3.0T continues to deliver the best possible fuel economy for years to come.