21 MPG isn’t a headline-grabbing number, but it accurately reflects what the 2016 Cadillac XTS 3.6L aims to do: provide comfortable, spacious, American-style luxury. This isn’t a vehicle for those prioritizing outright efficiency. It’s a car for those who value a smooth ride, a quiet cabin, and the prestige (and available features) that come with the Cadillac badge, even if it means sacrificing some miles per gallon.

City and highway performance

The EPA estimates for the 2016 Cadillac XTS with the 3.6L V6 and six-speed automatic transmission are 18 MPG in the city and 28 MPG on the highway. That highway figure is respectable, allowing for relaxed cruising on long road trips. The city number, however, is where the XTS makes its compromises. Stop-and-go traffic and the car’s substantial weight take a toll.

While 18 MPG is not egregious for a large sedan, it’s something to consider if your daily commute is primarily urban.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2016 Cadillac XTS 3.6L at $2,100. This figure is based on driving 15,000 miles per year and using the national average fuel price at the time of calculation. It’s a standardized metric, allowing buyers to compare the estimated running costs of different vehicles. Keep in mind that your actual fuel costs may vary depending on your driving habits, local gas prices, and the percentage of city versus highway miles you drive.

Aggressive driving will undoubtedly lower your MPG and increase that $2,100 figure.

Real-world expectations

The EPA figures offer a useful baseline, but what can you realistically expect? For most owners, especially those who do a mix of city and highway driving, the combined MPG will likely hover around the stated 21 MPG. However, if you spend most of your time in congested urban environments, you might see figures closer to the 16-17 MPG mark.

Conversely, long highway trips at consistent speeds can push the MPG closer to, or even slightly above, the 28 MPG estimate. Regular maintenance, proper tire inflation, and smooth driving habits play significant roles in achieving optimal fuel economy.

How it compares

When considering the 2016 Cadillac XTS 3.6L, it’s important to look at its competitors. The Lincoln Continental, another large American luxury sedan, with its standard 3.7L V6, offered similar fuel economy figures, around 17 MPG city and 25 MPG highway, making the XTS slightly better on the highway. A similarly equipped Lexus ES 350, while not as large, achieves a significantly better 21 MPG city and 31 MPG highway, reflecting its focus on efficiency and lighter weight.

Even within the Cadillac lineup, checking all Cadillac fuel economy data reveals that smaller sedans and crossovers offer superior fuel economy, though they lack the XTS’s spaciousness. Buyers must weigh the importance of fuel economy against the XTS’s other attributes. Before making a decision, you can also compare the XTS MPG across all years.

Tips to maximize efficiency

Gentle acceleration is key to maximizing fuel economy in the XTS. The 3.6L V6 offers strong power, but using it all the time will diminish MPG. Drive smoothly, anticipate traffic conditions, and avoid aggressive acceleration from stoplights.

Maintain proper tire inflation. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Check your tire pressure regularly and inflate them to the recommended pressure listed on the driver’s side doorjamb.

Reduce unnecessary weight. Carrying extra cargo in the trunk adds weight and reduces fuel economy. Remove any unnecessary items to lighten the load and improve efficiency, especially if you frequently drive in the city.

Minimize idling. Letting the engine idle for extended periods consumes fuel unnecessarily. If you’re stopped for more than a minute or two, it’s generally more efficient to turn off the engine and restart it when you’re ready to go.

Use cruise control on the highway. Maintaining a consistent speed helps optimize fuel economy. Use cruise control on long highway drives to avoid fluctuations in speed and maintain a steady, efficient pace.