23 MPG combined might seem underwhelming, but for the 2021 Jeep Wrangler Rubicon 4dr EcoDiesel 4WD 3.0L 6-cyl, it’s considerable. This is a serious off-road machine, not a commuter car. This vehicle is designed to crawl over rocks, ford streams, and generally handle unpaved roads. Owners want the torque to conquer any terrain, and the EcoDiesel delivers that with reasonable fuel consumption.

City and highway performance

The EPA estimates of 21 MPG in the city and 26 MPG on the highway show the compromises in a vehicle like the Wrangler Rubicon. Its aerodynamics are best described as “brick-like,” and its solid axles and knobby tires aren’t optimized for fuel sipping. The city figure suffers from the Wrangler’s weight and the need to work the engine harder in stop-and-go traffic. The highway number benefits from the diesel’s efficiency at cruising speeds and the eight-speed automatic transmission, which allows for relatively low RPMs. These numbers should be considered carefully, as aggressive driving or the addition of aftermarket accessories (lift kits, larger tires, heavy bumpers) will affect them.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2021 Jeep Wrangler Rubicon EcoDiesel at $2,400. This figure is calculated based on driving 15,000 miles per year, using the EPA’s combined MPG rating and assuming a national average fuel price. The actual amount will vary depending on driving habits, location, and fuel prices, but this provides a benchmark for comparison shopping. Diesel fuel prices can fluctuate, impacting this annual cost.

Real-world expectations

While the EPA provides a baseline, real-world fuel economy for the Wrangler Rubicon EcoDiesel depends on driving style, terrain, and modifications. Drivers who spend more time off-road or in heavily modified Wranglers should expect significantly lower MPG than the EPA estimates. On the other hand, those who primarily use their Wranglers for commuting on relatively flat roads might see MPG closer to or slightly above the highway figure. Consistent highway driving at moderate speeds helps maximize fuel efficiency with this vehicle.

How it compares

The Wrangler Rubicon EcoDiesel occupies a unique niche, making direct comparisons challenging. A similarly equipped Toyota 4Runner 4×4, with its gasoline V6, struggles to achieve even 20 MPG combined. The new Ford Bronco, particularly the Sasquatch package, is a closer competitor in terms of off-road capability, but its fuel economy with the 2.7L EcoBoost engine hovers around 17 MPG combined. A Jeep Gladiator with the same EcoDiesel engine delivers similar MPG numbers to the Wrangler. Consider also the WRANGLER MPG across all years to find the best combination of features and efficiency for your particular needs. Those drawn to the Wrangler Rubicon typically prioritize off-road prowess and capability over fuel efficiency, accepting the trade-off for its abilities.

Tips to maximize efficiency

Gentle acceleration helps get the most miles out of each gallon of diesel. The EcoDiesel engine provides ample low-end torque, so there’s no need to stomp on the accelerator. Smooth inputs will improve fuel economy, especially in city driving.

Maintain proper tire inflation. The Rubicon’s knobby tires offer off-road traction, but they also contribute to rolling resistance. Ensuring they are inflated to the recommended pressure reduces drag and improves fuel economy. Consistent tire pressure checks are essential.

Minimize unnecessary weight. The Wrangler Rubicon is already a heavy vehicle, so avoid adding unnecessary cargo or aftermarket accessories. Every extra pound adds to the engine’s workload and reduces fuel efficiency. Consider removing items when not needed for trips to remove extra weight and improve your fuel economy. Consider all Jeep fuel economy data when making any modifications.

Avoid prolonged idling. Diesel engines are generally more efficient than gasoline engines at idle, but idling still wastes fuel. If you’re stopped for more than a minute or two, turn off the engine. Restarting is more efficient than letting the engine run unnecessarily.

Service the diesel particulate filter (DPF) correctly. The EcoDiesel’s DPF captures soot to improve emissions. Follow the manufacturer’s recommendations to ensure the DPF functions properly. Neglecting maintenance can lower fuel economy and lead to repairs.