17 MPG combined is the defining compromise for the 2024 Lexus GX 550. It’s a number that will dissuade some buyers immediately, while others will readily accept it as the cost of admission for a truly capable and reliable luxury SUV. This isn’t just for driving to the store; it’s a truck-based machine designed to conquer trails and haul gear, all while cocooning its occupants in Lexus comfort.

City and highway performance

The EPA estimates the GX 550 achieves 15 MPG in the city and 21 MPG on the highway. The city figure reflects the inherent inefficiencies of a large, body-on-frame vehicle navigating stop and go traffic. The GX’s weight and its 10-speed automatic transmission, while smooth, are constantly working to overcome inertia. The highway number, while better, still isn’t stellar. The GX’s upright design isn’t particularly aerodynamic, and the standard four-wheel-drive system saps some efficiency even when cruising at a steady speed. These numbers reflect the GX’s focus: capability first, fuel economy second. It’s a trade-off the target buyer willingly makes.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2024 Lexus GX 550 at $3,400. This figure is based on driving 15,000 miles per year and using national average fuel prices. Keep in mind that this is an estimate, and your actual fuel costs may vary depending on your driving habits, the type of fuel you use, and local gas prices. If you drive significantly more than 15,000 miles per year, or live in an area with high fuel prices, expect to spend considerably more than $3,400 annually to keep your GX fueled.

Real-world expectations

While the EPA numbers provide a baseline, real-world fuel economy often deviates. GX 550 owners who frequently engage in off-road driving or towing will likely see their MPG dip below the EPA estimates. Aggressive driving habits, such as rapid acceleration and hard braking, will negatively impact fuel efficiency. However, those who primarily use their GX for highway cruising and practice fuel-efficient driving techniques might see slightly better numbers.

Expecting a significant improvement over the EPA ratings is unrealistic because the GX 550 is not designed to be a fuel sipper.

How it compares

Compared to its competitors, the GX 550’s fuel economy is predictably challenged. The Land Rover Defender 110 with its P300 engine achieves a combined 19 MPG, slightly better than the GX, but sacrifices some of the Lexus’s renowned reliability. The Jeep Grand Cherokee L with the V6 engine manages around 21 MPG combined. Even the Toyota 4Runner, with which the GX shares some DNA, achieves only a similar 17 MPG combined. These comparisons highlight the GX’s position in the market: a luxury SUV that prioritizes off-road capability and reliability over fuel efficiency.

For buyers primarily concerned with fuel economy, alternatives like the Acura MDX (22 MPG combined) or the Lexus RX (25 MPG combined) offer significantly better numbers, albeit with less off-road prowess. You can also review GX MPG across all years for a broader understanding of how this model’s efficiency has evolved.

Tips to maximize efficiency

While the GX 550 isn’t inherently fuel-efficient, there are steps owners can take to minimize fuel consumption. Avoid aggressive acceleration and hard braking. The GX is a heavy vehicle, and abrupt changes in speed require a significant amount of energy. Gradual acceleration and smooth braking will conserve fuel.

Ensure that your tires are properly inflated. Underinflated tires create more rolling resistance, which reduces fuel economy. Check your tire pressure regularly and inflate them to the recommended pressure specified on the door jamb.

Minimize unnecessary weight. The heavier the vehicle, the more fuel it consumes. Remove any unnecessary items from the cargo area to reduce the overall weight of the GX.

Consider using a less aggressive tire when not regularly off-roading. The GX’s standard all-terrain tires, while excellent for off-road traction, can increase rolling resistance on paved roads. Switching to a less aggressive tire design can improve fuel economy slightly.

Plan your trips efficiently. Combine errands and plan routes to avoid stop and go traffic whenever possible. Idling consumes fuel, so avoid prolonged idling when possible. Explore all Lexus fuel economy data to see how this model’s numbers fit into the broader Lexus lineup.