Eighteen miles per gallon combined is a number luxury car buyers typically don’t sweat, and that’s especially true for someone seeking a 2018 Jaguar XJ with the 5.0-liter V8. This isn’t a car for hypermilers; it’s for executives who value a unique blend of British luxury and strong performance. Fuel economy takes a back seat to the XJ’s distinctive character and the powerful driving experience afforded by its potent engine.

City and highway performance

The EPA estimates for the 2018 Jaguar XJ 5.0L V8 place city driving at 15 MPG and highway driving at 23 MPG. These figures reflect the inherent compromise between the car’s significant power output (340hp – 470hp depending on trim) and its mass. The XJ, even with its aluminum-intensive construction, is not a lightweight, and the V8 engine needs fuel to deliver its effortless acceleration. The eight-speed automatic transmission, while smooth and responsive, is geared to maximize performance, not necessarily fuel sipping. That said, the highway figure of 23 MPG is reasonable for a large sedan with a powerful engine, making long-distance cruising relatively efficient, considering the car’s capabilities. The city estimate is more telling, as stop-and-go traffic will inevitably dip below 15 MPG. Explore XJ MPG across all years for comparison.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2018 Jaguar XJ 5.0L V8 at $3,200. This calculation is based on driving 15,000 miles per year and using national average fuel prices. It’s a useful benchmark, but individual fuel costs will vary depending on driving habits, local fuel prices, and the percentage of city versus highway driving. Consider this figure a starting point for understanding the ongoing expense of owning and operating this particular model.

Real-world expectations

While the EPA provides a standardized estimate, real-world fuel economy for the 2018 Jaguar XJ 5.0L V8 will often deviate from the official numbers. Aggressive driving, frequent short trips, and neglecting regular maintenance can all negatively impact fuel efficiency. Conversely, gentle acceleration, consistent highway speeds, and meticulous upkeep can help owners achieve figures closer to the EPA estimates, or even slightly better. Keep in mind that the “S” driving mode, while enhancing throttle response and shift points, will invariably consume more fuel than the standard “D” mode. The best way to gauge real-world fuel economy is to track it manually over time, using a fuel log or smartphone app.

How it compares

In the 2018 model year, the Jaguar XJ 5.0L V8 competes with other luxury flagship sedans that prioritize power and prestige over outright fuel efficiency. For example, the BMW 750i xDrive, with its 4.4-liter V8, achieves a combined 19 MPG, slightly edging out the XJ. The Mercedes-Benz S560, boasting a 4.0-liter V8, manages a combined 20 MPG. While these German rivals demonstrate a marginal improvement, the difference is unlikely to sway buyers primarily drawn to the XJ’s unique design, handling, and British heritage. The Audi A8, with its standard V6, offers better fuel economy at 22 MPG combined, but also lacks the aural excitement of the V8. Buyers cross-shopping these vehicles should be aware of all Jaguar fuel economy data and other brands to see what best fits their driving style and budget.

Tips to maximize efficiency

One of the most effective strategies for improving fuel economy in the 2018 Jaguar XJ 5.0L V8 is to drive smoothly and avoid hard acceleration. The V8 engine is responsive, but excessive throttle input will rapidly deplete fuel. Anticipate traffic flow and maintain a consistent speed whenever possible to minimize unnecessary braking and acceleration.

Regular maintenance is critical for optimal fuel efficiency. Ensure that the engine oil is clean and at the correct level, the air filter is clean, and the tires are properly inflated. A well-maintained engine will run more efficiently and consume less fuel, while properly inflated tires reduce rolling resistance.

Minimize idling time. If you anticipate being stopped for more than a minute, turn off the engine. Modern engines are designed to restart quickly and efficiently, and avoiding prolonged idling can save a significant amount of fuel, especially in city driving. Don’t let vanity features like seat coolers and warmers run needlessly, these require additional power.

Consider using premium fuel as recommended by Jaguar. While the engine may run on regular fuel, using premium fuel can sometimes improve performance and fuel economy, especially under demanding driving conditions. However, always consult the owner’s manual for specific recommendations.