SEDONA, ARIZONA—People don’t usually associate Range Rovers with fuel economy, but in fact their aluminum-intensive construction lightens them more than you’d think, and when you combine that with a diesel engine, you’re ready to break new ground.

The new Range Rover Td6 and Sport Td6, now on sale, achieve 29 mpg on the highway, and 25 combined (I averaged 23.5 mpg), which is great for the class. I drove a Td6 and an HSE with the same engine in their natural element — dirt roads worthy of the worst Costa Rica throws at you — in the new age surrounds of Sedona, Arizona. I even got my aura read (it was light blue).

Range Rover Td6The Td6 proved more than capable in an off-road course. (Photo: Jim Motavalli)

The new Range Rover diesels, the first-ever for the North American market, are debuting amid the fallout around the Volkswagen scandal, which is why Peter Wright, vehicle engineering manager at Land Rover, was at pains to point out that these cars have no bogus emissions control devices or defeat software.

Surrounded by hugely colorful buttes and arroyos — as well as the occasional startled mule deer (no gila monsters, thankfully) — we scaled boulders the size of well, Volkswagens. I was OK at this, but an ex-military off-road expert in the passenger seat certainly helped. And if off-roading seems outside your comfort area, Range Rover offers all-terrain progress control (ATPC), a sort of cruise for low-speed rock climbers (it tops off at 19 mph).

Td6 engineThe three-liter Td6 engine produces 254 horsepower and a stump-pulling 440 pound feet of torque. But don't forget to add the AdBlue. (Photo: Jim Motavalli)

ATPC is a bit uncanny. Switch the system on and steer only — the car appears to think out each obstacle and scales it with a deft stab on the throttle and some carefully applied torque. At 10 mph, it’s a bit in slow motion — serious off-roading is life in the turtle lane unless you want to spend serious money with your mechanic.

VW cheated because it was having trouble controlling nitrogen oxide in its four-cylinder diesels; the Range Rovers reduce NOx with an exhaust gas recirculation system that feeds into the turbocharger, and selective catalytic reduction (SCR) that breaks NOx down into its component parts. That means maintaining a diesel exhaust fluid (DEF) tank, a step VW avoided. Customers (or the dealer) replenish the AdBlue fluid through a filler under the hood every 5,000 to 10,000 miles. It’s no big deal, especially when the alternative is bad air pollution.

Increasing the diesel percentage in Land Rover’s U.S. take rate faces some headwinds. The company would like to see 20 percent of its range with diesel under the hood, but the VW scandal looms — through no fault of the British company. More than half of Land Rover’s sales worldwide are diesels, and in Europe it’s more like 90 percent, but the U.S. has long been diesel-phobic. Just 4.6 percent of vehicles sold in 2014 were diesels.

Range Rover Td6 interiorInterior luxury is a big part of the Range Rover's appeal, even when it's axle deep in mud. (Photo: Jim Motavalli)

Land Rover’s Jaguar sibling is also unveiling diesels, with up to 40 mpg fuel economy. It’s not hard to see the appeal, especially of the three-liter, 254-horsepower Td6 engine. It’s incredibly quiet, torque-y (440 pound feet) and responsive. You get an incredible 658 miles of range. A Land Rover test showed few drivers could tell they were driving a diesel, and I certainly wouldn’t have been aware of it.

It’s a gamble, but diesel customers might well like what they find. The Range Rover Td6 starts at $66,450, and the Sport model at $86,450.

Here's a video look at the Td6 that points out that diesel Range Rovers have been a staple in other markets for 30 years:

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.