We've known for a while that the new Jeep Gladiator is set to offer two engine options: a 3.6-liter Pentastar V6 producing 285 horsepower and 260 lb-ft of torque (available at launch) and an upcoming 3.0-liter turbo-diesel V6 rated at 260 hp and 442 lb-ft of torque. Jeep still hasn't announced when the diesel-powered Gladiator will go on sale, but recent spy shots from various outlets have us focusing on another potential diesel model.

Spy shots typically show some sort of prototype vehicle, usually under heavy camouflage, trying to hide some big secret. But this case is rather different. A Wrangler Unlimited Sahara was spotted completely uncamouflaged but wearing a very distinct badge on the rear.

The badge reads '3.0 D' with a smaller engraving underneath the D reading 'Diesel.' A diesel-powered Wrangler has been in the rumor mill since 2018 when leaked order codes brought a flurry of attention to the oil-burning model. With the arrival of this test mule, it seems like only a matter of time before Jeep finally announces a diesel-powered Wrangler. Perhaps the company is waiting to announce pricing and specifications for the diesel Gladiator in order to reveal both at the same time. We still don't know what the fuel economy or towing specifications will be, but we expect the diesel Gladiator and Wrangler to be rated at 260 hp and 442 lb-ft of torque.

Jeep is also working on a 2.2-liter four-cylinder diesel engine rated at 197 hp and 331 lb-ft of torque, but this motor will be for Europe only. The diesel engines in the Gladiator and Wrangler will likely offer fuel efficiency benefits over the gas V6 but should come with a hefty price premium. We expect Jeep to make an official announcement later this year, though availability may not begin until 2021.