Autonomous Off-Roading With the Diesel Range Rover Td6

Sure, diesel is is getting a bad rap right now.

In any unpaved driving scenario, there are two key factors at play: the capabilities of the driver, and the capabilities of the vehicle. I’ve dabbled enough in off-roading to know how to handle modest challenges, but tackling the craggy hills outside of Sedona, Arizona, in the new Range Rover Td6 and the Range Rover Sport Td6 — the first-ever appearance of diesel Land Rovers in the US — completely re-calibrated my idea of off-road excellence in road-ready SUVs.

Here you have the already legendary Land Rover prowess, boosted by a new All-Terrain Progress Control system that automatically controls throttle and braking to scramble brilliantly over rocky terrain — down to even a 1 mph crawl. All that, on top of the power and efficiency of a modern diesel engine. Together these polished brutes grunt their way up the steepest hills and over the gnarliest rocky outcrops. Undoubtedly the greatest pairings yet of royal grace and Tough Mudder muscle.

But wait, you say. What about that Volkswagen mess?!?!

While the Dieselgate debacle is an unmitigated disaster that could indeed spell doom for the fuel’s widespread adoption in the United States and elsewhere, for now other companies that truck in diesel tech are proceeding as if it’s business more-or-less as usual. Land Rover’s diesel rollout has been in the works for years, and even the worst timing can’t easily derail that — especially given that Land Rover swears up and down that its diesel vehicles pass emissions with no cheats or shortcuts.

Range Rover and Range Rover Sport Td6 Stats


Engine: 3.0-liter, 24-valve Diesel Turbocharged V6
Transmission: eight-speed controlled automatic
Horsepower: 254
Torque: 443 lb-ft
Drive Type: four-wheel-drive
MSRP: $66,450

Which is remarkable, given the way diesel benefits these trucks. Both use the same basic engine, a 254 horsepower turbocharged V6 that produces 443 lb-ft of torque, which arrives at an off-road-friendly 1,750 RPM. Diesel exhaust is managed not via deeply embedded illegal code, but by a Selective Catalytic Reduction system, which injects neutralizing agent into the exhaust to convert nitrogen oxide emissions into harmless nitrogen gas. (The fluid can be easily topped off by owners.) There is also a range of engine modifications to further keep emissions down, including lower combustion temperatures and improved fuel injection. The net result is a 30 percent fuel-efficiency improvement over the gasoline Rovers, bringing it up to a significantly good 25 mpg combined city/highway. With that — and 23.5-gallon tank — comes a range of 658 miles.

The engines are also quiet. Engine mounts isolate vibration and a revised bulkhead design keeps acoustic signatures to a minimum, and the diesel “knock” has been knocked out courtesy of a two-stage injection cycle. From outside either Range Rover, you can barely tell it’s a diesel. Inside it’s as quiet as Balmoral Castle on a Sunday morning.

On the highway, road manners are great, with brisk acceleration to 60 mph in only 7.4 seconds for the Range Rover and 7.1 seconds for the Sport — thanks largely to the prodigious low-end torque. Midrange 60-80 mph passing power left a little to be desired, so make sure you have the space. Thankfully, the ride is characteristically Range Rover: smooth and responsive. The air suspension helps optimize ride height: down low for slithering through turns or boring holes in highway slipstreams; up high for clearing cluttered trails.

The computers sense precisely what you’re tackling, uphill or down, and then mitigate wheel spin and assign torque wherever it is needed most.

In Sedona I navigated steep, rocky slopes with ease — slowly, it should be said, but with ease — thanks to the advanced terrain navigation system. The computers sense precisely what you’re tackling, uphill or down, and then mitigate wheelspin and assign torque wherever it is needed most. As a result, you merely steer and occasionally adjust speed using the cruise control buttons. Though it’s tempting to intervene more, if your speed is dialed in properly the computers manage any obstacle the truck is designed to clear. It’s a fun confidence-booster for those who may not feel great about dicey, or even perilous, terrain. Just let the car do the thinking, and let the diesel do the grunting. Off-road pros can tackle the terrain however they like; noobs can lean on 21st-century tech to keep them out of trouble.

So what to make of these particular machines in today’s infinitely troubled diesel tech landscape? Diesel Land Rovers — long available in the rest of the world — couldn’t have debuted in the United States at a worse time, but they’re here and they’re bringing the true thunder, instead of mere smoke and mirrors. The same is true of other manufacturers — namely BMW and Mercedes-Benz, who also opt for the more complex but perfectly viable strategy of exhaust treatment to suppress emissions. Will they all survive Dieselgate in the long run? It’s impossible to say, of course, but even the gut-punch that diesel suffered courtesy of VW’s subterfuge can’t diminish the fuel’s ultimate potential — especially when that potential is delivered by grown-ups looking to harness its power and performance for all the right reasons, off-road or not.

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