The Jeep Gladiator is a unique proposition on the truck market, offering the personality of a Wrangler in a longer, more cargo- and towing-friendly form. Of course, that means it comes with all of the compromises of a Wrangler, including a rather soulless standard 3.6-liter V6. While the corporate Pentastar engine does well enough in cars and minivans, it’s not torquey enough for off-road truck duty. Enter the 2021 Jeep Gladiator EcoDiesel.

It’s not all that surprising to see Jeep offer the 3.0-liter EcoDiesel V6 on the Gladiator, given it arrived in the Wrangler Unlimited for the 2020 model year. Available on every trim level but the Mojave, the turbodiesel mill thoroughly transforms the Gladiator’s character, both on-road and off, by adding more torque over the standard Pentastar V6. Even though it technically loses some ponies, trust us, you won't miss them."

Husky Hauler

Adding 178 pound-feet can have that effect – the Gladiator EcoDiesel produces 442 stump-pulling units of twist, compared to just 260 for the Pentastar V6. Accompanying that torque is 260 horsepower, down 25 compared to the gasser.

In around-town driving, the Gladiator EcoDiesel has some unavoidable turbo lag, but off-the-line response is at least as good as the gas V6. And once that turbocharger kicks in, a smooth rush of torque – with a peak that lasts from 1,400 to 2,800 rpm – pushes the decidedly un-aerodynamic Gladiator through the breeze with authority. Passing and merging maneuvers that might require a flat foot in the Pentastar only need a big toe’s worth of pressure in the EcoDiesel, its eight-speed automatic gearbox doling out twist dutifully without requiring a screaming downshift.

2021 Jeep Gladiator EcoDiesel Exterior Rear Off-Road Flex

The small-displacement diesel also produces only a little perceptible shake at idle, and the behavior smooths out completely once underway. What’s more, with the doors and roof panels installed, the oil-burning power plant under the hood makes its presence known with a mere whisper of diesel clatter, growing in volume (but not harshness) when the driver adds some throttle. Diesel owners appreciate some audible feedback that they’re driving something a bit different, so the noise is totally welcome in this application.

And surprisingly, the much heavier EcoDiesel improves the Gladiator’s on-road handling somewhat – equivalent models gain about 300 pounds in the switch from Pentastar to EcoDiesel. The engine’s extra weight calms down the vague, meandering front end, giving the driver more confidence on twisting roads and at speed.

The trailer weight rating tells a different story. In spite of its added grunt, the EcoDiesel’s maximum towing capacity is only 6,500 pounds, down from the 3.6-liter V6’s 7,650. The Gladiator Rubicon EcoDiesel, meanwhile, is only rated to tow 6,000 pounds, down from the gasser’s 7,000. Jeep admitted that the seven-slot grille couldn’t provide the airflow needed to keep the turbocharged diesel cool when lugging that much weight, and the Gladiator’s solid bumpers and short front overhang don’t leave enough space to mount an auxiliary engine cooler. Nevertheless, we suspect an EcoDiesel would still haul with more authority up to that max than a Pentastar.

Clean Diesel, Dirty Fun

2021 Jeep Gladiator EcoDiesel Exterior Front Off-Road Flex

To no one’s surprise, the Gladiator is a riot off-road. On the steep, narrow trail Jeep chose for our drive, an EcoDiesel-equipped Rubicon might as well have been a bighorn sheep for how adroitly it handled obstacles. As on gas-equipped Gladiators, the EcoDiesel Rubicon gets a two-speed transfer case with a shorter low range – 4.0:1 as opposed to 2.72:1 on the Sport and Overland. The diesel engine’s brawny twist and the transfer case’s aggressive torque multiplication allow the Gladiator to idle over large obstacles, even without throttle application. That kind of control in off-road situations is a wonderful thing.

Helping in the truck’s rugged mission are the Rubicon’s standard selectable front and rear lockers. The locked differentials provide plenty of traction, ensuring power gets to the ground even when one wheel is in the air. Preventing that phenomenon is the work of the electronic-disconnecting front sway bar. With the sway bar disengaged, axle articulation is incredible, helping keep both front wheels on the ground even when traversing a large ditch diagonally or driving through rutted terrain.

Although our time off-road was short, it was enough to prove that the presence of the hulking EcoDiesel’s V6 torque would only improve the Gladiator’s off-road aspirations.

2021 Jeep Gladiator EcoDiesel Front Suspension
2021 Jeep Gladiator EcoDiesel Front Suspension

Making Cents

The EcoDiesel demands $4,000 over an equivalent, automatic-equipped Pentastar Gladiator, and since the EcoDiesel isn’t available with a manual transmission, it costs $6,000 over the base powertrain. That brings the Gladiator Sport EcoDiesel’s base price up to $39,545 plus $1,495 for destination, while the Rubicon starts at $49,875. At the top of the range is the luxurious Gladiator High Altitude, demanding $55,500 for the EcoDiesel variant plus destination and options.

Improved fuel economy helps blunt that cost – the EPA rates the Gladiator EcoDiesel at 22 miles per gallon city, 28 highway, and 24 combined, while the Gladiator Rubicon achieves 21 city, 27 highway, and 24 combined. That’s up from an auto-equipped Pentastar’s 17, 22, and 19 mpg.

Gallery: 2021 Jeep Gladiator EcoDiesel First Drive

Of course, it would still take a decade or more to make that extra investment back in fuel savings, so electing the EcoDiesel over the 3.6-liter Gladiator is a matter of preference, not economy. The torque-rich engine helps the Gladiator fit in more easily with traffic, and improved handling further helps matters. We also think the reduced towing capacity is fairly immaterial – folks who regularly haul 7,000 pounds or more would be better off in an entry-level full-size pickup with a longer, more stable wheelbase.

As popular as the Gladiator and Wrangler are, the EcoDiesel is probably destined to be a niche product. Jeep specifically points to overlanders, who would appreciate the engine’s range between refueling, and there’s probably a strong contingent of Moab acolytes who’d make great use of the broad, high torque curve on tricky sections of rock. Anyone seeking those attributes won’t be disappointed, while the rest of us can take solace in every Gladiator’s fun-to-drive attitude and unique style.


2021 Jeep Gladiator EcoDiesel

Engine 3.0-Liter Turbodiesel V6
Output 260 Horsepower / 442 Pound-Feet
Transmission 8-Speed Automatic
Drive Type Four-Wheel Drive (Part-Time)
Efficiency 22 City / 28 Highway / 24 Combined
Weight 5,300 Pounds (est.)
Seating Capacity 5
Towing 6,000 Pounds
Payload 1,075 Pounds
Cargo Volume 35.5 Cubic Feet
Base Price $49,875
As-Tested Price $62,000 (est.)
Got a tip for us? Email: