18 MPG. That’s the combined EPA fuel economy for the 2015 Jaguar XJ FFV with the 5.0L V8. It’s not an impressive number. However, focusing only on this figure is to misunderstand the XJ and what it offers. People interested in this car aren’t prioritizing how much gas it saves; they want a British combination of sporty handling and classic luxury that few competitors can match.

City and highway performance

The EPA estimates the XJ’s fuel economy at 15 MPG in the city and 23 MPG on the highway. The city number shows how much gas the engine uses in stop-and-go traffic. The XJ isn’t very light, and that V8 has to work to move it. The highway number is a little better, but still lags behind many competitors. This shows that even on the open road, a large engine without a turbocharger isn’t the most efficient.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2015 Jaguar XJ FFV 5.0L at $3,200. This is based on driving 15,000 miles per year and using national average fuel prices. Premium fuel is recommended for the XJ’s 5.0L V8, which increases the fuel cost compared to cars that use regular gas.

Real-world expectations

The EPA’s numbers are a starting point, but actual fuel economy can change based on driving habits, traffic, and weather. Quick acceleration, frequent hard braking, and a lot of idling will all hurt your mileage. On the other hand, smooth, careful driving can help you get closer to the EPA highway number, although matching it in mixed conditions will be hard. Owners should check resources like FuelEconomyHub for XJ MPG across all years to see figures submitted by other drivers.

How it compares

The 2015 Jaguar XJ FFV 5.0L is near the bottom for fuel economy compared to its rivals. A 2015 BMW 750i xDrive, with its turbocharged V8 and all-wheel drive, gets around 19 MPG combined. The Mercedes-Benz S550 from the same year gets a similar number. Even though the XJ has rear-wheel drive only (in this version), the others show the fuel efficiency benefits of turbochargers and newer engine computers. The Audi A8 3.0T, with its supercharged V6, gets a better 22 MPG combined. This comparison is important for luxury car shoppers who are also thinking about fuel costs, especially those who drive more than 15,000 miles per year.

Tips to maximize efficiency

One of the biggest changes you can make is to drive more smoothly. Avoid quick acceleration and hard braking. Watch the traffic and keep a steady speed when you can. The XJ’s 8-speed automatic transmission is designed to shift up quickly in normal driving, which keeps the engine in its most efficient range. Let it do its job.

Regular maintenance is also important. Keep your tires inflated to the right pressure, since tires that are not inflated enough increase rolling resistance and cut down on fuel economy. Make sure the engine is tuned correctly and that all maintenance is done on time. A well-maintained engine is an efficient engine. Owners can find all Jaguar fuel economy data on FuelEconomyHub to compare their own mileage.

Minimize idling. If you’re going to be stopped for more than a minute, turn off the engine. Modern cars can restart quickly and efficiently, and you’ll save gas over time. This is especially true in city driving where there’s more idling.

Take out extra weight. Remove anything from the trunk or back seat that you don’t need. Extra weight makes the engine work harder, which lowers fuel economy, something obvious that should still be mentioned.