Ram Trucks’ striking Rebel off-roader may be getting all the headlines at the 2015 Detroit Auto Show, but the brand’s 1500 EcoDiesel HFE has some charm of its own.

The American brand announced the fuel-efficient HFE model at the event on Tuesday, which adds a bevy of aerodynamic aids to reduce strain at the gas pump.

The full-size truck comes equipped with stop-start technology, wheel-to-wheel side steps, and a tri-fold bed cover. These may seem like minor changes over the standard model, but the truck now returns class-leading economy ratings of 21 mpg city, 29 mpg highway, and 24 mpg combined.

This is only possible with the 3.0-liter EcoDiesel engine, mind you, but for a vehicle of this size, those numbers are very impressive. The light-duty powerplant generates 240 horsepower and 420 pound-feet of torque.

For comparison’s sake, the 2015 Ford F-150 boasts 19 mpg in the city, 26 mpg on the highway, and 22 mpg combined with the 2.7-liter EcoBoost V6, its most fuel-efficient offering. With 325 hp on tap, the gas-powered EcoBoost is much more powerful than the Ram, but for fuel savings, the HFE is the way to go.

“Fuel efficiency is at the top of truck buyers’ priorities, and Ram is the recognized benchmark for the industry,” said Bob Hegbloom, President of Ram Trucks. “Twenty-nine miles per gallon cuts through the clutter. Ram invested in powertrain technologies and those are paying real dividends in the wallets of our customers.”

Related: Ram Trucks’ new 1500 pickup is a ‘Rebel’ with a mud-flinging cause

The “fuel economy king” isn’t just about gas savings, though; it wears 20-inch wheels, a body-colored front fascia, and the trim package from the Ram 1500 Tradesman model.

Pricing for the HFE hasn’t been announced yet, but the pickup will go on sale in the first quarter of 2015.