18 MPG is the combined fuel economy figure for the 2016 Jaguar XJ with its 5.0-liter V8. To be clear: nobody buys an XJ with this engine primarily for fuel efficiency. They buy it for the effortless power, the refined growl, and the feeling of occasion on every drive. Fuel economy is simply the price to pay to enjoy those features.

City and highway performance

The EPA estimates the XJ V8 will achieve 15 MPG in the city and 23 MPG on the highway. The city number reflects stop-and-go traffic and the engine’s eagerness to deliver power, which uses more fuel. The highway figure improves as the engine settles into a cruising speed, but even then, the XJ’s weight and aerodynamic profile prevent it from achieving truly impressive numbers. The eight-speed automatic transmission helps optimize fuel consumption at various speeds, but ultimately, it’s working against a large engine designed for performance, not efficiency.

Annual fuel cost

The EPA estimates an annual fuel cost of $3,200 for the 2016 Jaguar XJ 5.0L. This figure is based on driving 15,000 miles per year, a blend of city and highway driving, and the national average fuel price. Premium fuel is recommended for the XJ’s V8 engine to ensure optimal performance. Using regular fuel might seem like a way to save money, but it could lead to reduced performance and potential engine damage over the long term. Therefore, the $3,200 figure is based on the price of premium fuel.

Real-world expectations

Real-world fuel economy for the XJ V8 will vary depending on driving style, traffic conditions, and the roads driven. Drivers who prioritize rapid acceleration and frequent bursts of power should expect to see numbers closer to the city estimate, or even lower.

Those who primarily drive the XJ for long highway journeys, maintaining a steady speed, may achieve figures closer to or slightly above the 23 MPG highway rating. Careful monitoring of driving habits and sticking to recommended maintenance schedules can also influence fuel economy.

How it compares

The XJ’s fuel economy is lower compared to competitors offering smaller engines or hybrid powertrains. For instance, the BMW 740i, with its turbocharged inline-six, achieves a combined 25 MPG. Even the Mercedes-Benz S550, with its twin-turbo V8, manages around 20 MPG combined. The Audi A8 with the supercharged V6 also performs better than the XJ in terms of fuel efficiency, offering approximately 22 MPG combined. While XJ buyers appreciate the V8’s character, they may still want adequate fuel efficiency compared to other vehicles in this class. You can view XJ MPG across all years to see how efficiency has changed.

Tips to maximize efficiency

Avoid aggressive acceleration and hard braking. The XJ’s V8 is responsive, but gentle throttle inputs will significantly reduce fuel consumption. Anticipate traffic flow and maintain a consistent speed whenever possible. Using cruise control on the highway can also improve fuel economy.

Ensure that the tires are properly inflated to the recommended pressure. Underinflated tires increase rolling resistance, which can negatively impact fuel economy. Check the tire pressure regularly and adjust as needed.

Keep the XJ properly maintained. Regular oil changes, air filter replacements, and spark plug maintenance will ensure the engine is running efficiently. A well-maintained engine consumes less fuel.

Minimize idling. If you’re stopped for more than a minute, turn off the engine. Modern engines are designed to restart quickly, and idling wastes fuel and increases emissions. This is especially true given the XJ’s large displacement V8.

Reduce unnecessary weight. Remove any unnecessary items from the trunk and passenger compartment. Excess weight increases the amount of energy required to move the vehicle, which reduces fuel economy. See all Jaguar fuel economy data to compare.