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2021 Jeep Gladiator EcoDiesel review: A great engine upgrade, but it'll cost you

The Jeep Gladiator shines with its torque-tastic EcoDiesel engine. But is it worth the $6,000 upcharge?

Emme Hall Former editor for CNET Cars
I love two-seater, RWD convertibles and own a 2004 Mazdaspeed Miata for pavement fun and a lifted 2001 Miata for pre-running. I race air-cooled Volkswagens in desert races like the Mint 400 and the Baja 1000. I have won the Rebelle Rally, seven-day navigational challenge, twice and I am the only driver to compete in an EV, the Rivian R1T.
Steven Ewing Former managing editor
Steven Ewing spent his childhood reading car magazines, making his career as an automotive journalist an absolute dream job. After getting his foot in the door at Automobile while he was still a teenager, Ewing found homes on the mastheads at Winding Road magazine, Autoblog and Motor1.com before joining the CNET team in 2018. He has also served on the World Car Awards jury. Ewing grew up ingrained in the car culture of Detroit -- the Motor City -- before eventually moving to Los Angeles. In his free time, Ewing loves to cook, binge trash TV and play the drums.
Emme Hall
Steven Ewing
4 min read
2021 Jeep Gladiator EcoDiesel
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2021 Jeep Gladiator EcoDiesel

We love the rugged look of the Rubicon.

Steven Ewing/Roadshow

The pickup gets a new diesel engine option for 2021. It's the same 3.0-liter EcoDiesel V6 you'll find in the and , pushing out 260 horsepower and 442 pound-feet of torque. But with its $6,000 premium over the standard powertrain, is it good enough to warrant that extra cost?


2021 Jeep Gladiator EcoDiesel


  • Tons of low-end torque
  • Smooth highway manners
  • Fuel economy benefits
  • Unmatched off-road chops

Don't like

  • Diesel engine is expensive
  • Payload and towing ratings suffer

To find out, we head for the sand dunes of Glamis, California. Theoretically, at least, the increased low-end torque and revised gearing in the eight-speed automatic transmission should be a boon for off-roading, letting us keep momentum without needing to change gears. The other benefit of this engine is fuel economy, and the Gladiator Rubicon EcoDiesel is rated to return 22 miles per gallon combined. (Sport and Overland models can achieve 24 mpg.) After 500 miles of driving and a hard day in the dunes, we're seeing 21.8 mpg. Pretty good.

The Gladiator has an Off-Road Plus setting that sharpens the throttle response in four-wheel-drive high gear for quicker bursts of power if needed. The Gladiator has no trouble attacking dune faces, scrambling up and over hills without issue. It even powers out of a small, V-shaped hole in the dunes that can suck other vehicles in like quicksand, the Jeep's Falken Wildpeak 285/70R17 tires aired down to 17 psi for extra grip in the soft sand.

2021 Jeep Gladiator EcoDiesel hits the dusty trails

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With the Gladiator Rubicon's approach angle of 43.4 degrees, we can keep the front end straight and not worry about plowing into anything on the way up or down a dune. The Jeep also has 11.1 inches of ground clearance, though the Gladiator's wheelbase, which is longer than a Wrangler's, reduces the breakover angle to 20.3 degrees. Depending on the shape of the dune, this means carrying just enough speed to slide the Jeep over the crest, but not so much that the Gladiator launches into the air.

The Gladiator has no problem handling just about any off-roading scenario, including the rocks and ruts at California's Hungry Valley playground near Gorman. Again, the low-end diesel torque makes it easy to steadily modulate the power while climbing a steep rock face, and technologies like Selec Speed, which is essentially off-road cruise control, mean we can keep a steady pace without constantly having to work the throttle.

Jeep 3.0-liter EcoDiesel V6
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Jeep 3.0-liter EcoDiesel V6

The EcoDiesel engine is currently available in the Jeep Gladiator, Wrangler and Ram 1500.


Of course, the EcoDiesel engine isn't just great for off-roading. The smooth torque delivery means the Gladiator is great to drive on pavement, easily handling the steep grades of the Grapevine on California's I-5 freeway without the constant need to downshift. (We've driven the Gladiator with the gas-fed 3.6-liter V6 here and it's not nearly as good.) Combined with the Gladiator's long wheelbase and revised rear suspension, this is arguably the best setup for those who might need to do long treks on the highway, though it's still not what we'd call luxurious. It's more comfortable than a Wrangler, but still very much a Jeep.

Diesel engines are great for towing, but due to some engine cooling issues, Jeep actually recommends pulling a maximum of 6,000 pounds with the Gladiator Rubicon EcoDiesel. That's a full 1,000 pounds less than a truck equipped with the 3.6-liter V6. Payload drops a bit, too, from 1,160 pounds in the gas truck to 1,075 in the EcoDiesel.

Engine aside, the Rubicon EcoDiesel is largely the same as any other Jeep Gladiator. The interior materials are good, but not great, and there are a surprisingly large number of comfort and convenience amenities, especially for a truck so off-road focused. The leather seats offer heating and cooling, and niceties like full LED lighting, blind-spot monitoring and rear cross-traffic alert are available, albeit as options.

2021 Jeep Gladiator EcoDiesel
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2021 Jeep Gladiator EcoDiesel

It'll take you anywhere.

Steven Ewing/Roadshow

The optional 8.4-inch Uconnect infotainment screen is as good here as it is in any other Jeep, and includes off-road pages that show things like pitch, roll and your exact GPS coordinates. Apple CarPlay, Android Auto and a Wi-Fi hotspot are included with the $1,895 infotainment upgrade, too.

The one big demerit against the Gladiator EcoDiesel is its price. The diesel engine upgrade is a full $6,000 -- $4,000 for the engine itself and then $2,000 for the mandatory eight-speed automatic transmission. That brings the $45,370 starting price (including $1,495 for destination) of a Gladiator Rubicon up to $51,370. Load it up with options and you can almost hit $70,000. The truck seen here stickers for $64,495.

Sweet as the diesel engine is, we aren't sure it's worth the upgrade, considering the fuel economy benefits are pretty small. It makes the Gladiator nicer for on-road driving, sure, but every one of these trucks, regardless of engine, is a total champ off-road. We dig the EcoDiesel engine, but just as it is in the Wrangler, with its big price premium, it's not exactly a must-have option in this otherwise great truck.


2021 Jeep Gladiator EcoDiesel

Score Breakdown

Performance 9Features 9Design 8Media 8.5