The 2020 Jeep Wrangler EcoDiesel now has official EPA ratings. The ratings make this version of the Wrangler the most fuel efficient variant, with ratings following that of the Ram EcoDiesel, which shares its engine.

According to the EPA, the Wrangler EcoDiesel will be rated at 29 mpg highway and 22 mpg city, yielding a 25 mpg combined rating. That rating is specifically for the four-door automatic, which is the only variant that offers the optional 3.0-liter diesel V-6. By comparison, the Ram EcoDiesel is rated slightly lower.

Those ratings nudge out the current two-door, four-cylinder Wrangler to be the most-efficient version of the Wrangler. The most-efficient gas model is rated at 24 mpg highway, 22 mpg city and 23 mpg combined.

Despite the better fuel economy, this engine option isn’t likely to save buyers any money. Not only is diesel fuel more expensive, but the option to add the 3.0-liter EcoDiesel costs a whopping $4,000; an amount high enough to cancel out most of the potential fuel savings unless you’re driving on the highway almost exclusively.

Instead, Wrangler EcoDiesel buyers should focus on the hefty 442 pound-feet of torque this engine churns out, which will be a great addition for those who want to actually take their Wrangler off-road.