Electric or Diesel: BMW X5 xDrive40e vs. Range Rover Sport Td6

Two different ways to adjust to the changing climate

Large luxury SUVs are like cable television. There's still a big market out there, but it's becoming more difficult to stay current as the market changes at such a rapid pace. In television, the internet has been the disruptive force of change, while in the automotive industry, fuel efficiency and emissions regulations are pushing automakers to pursue ever more advanced technologies and solutions. But are diesel and electric variants of big SUVs like the Range Rover Sport Td6 and the plug-in hybrid BMW X5 xDrive40e really shaking things up Netflix- and Hulu-style?

 

Nothing new about diesel

The Range Rover Sport Td6 is but the latest stop on a well-traveled path, beaten down over the years with plenty of diesel engines. After all, diesel engines are already installed in 90 percent of Range Rover models sold in Europe. The 3.0-liter turbodiesel V-6 under the Rover's hood makes 254 horsepower and 443 lb-ft of torque, and it improves fuel economy by a whopping 6 mpg combined compared to the Range Rover Sport's standard 3.0-liter supercharged gasoline V-6. And now that diesel emissions are under so much scrutiny due to the Volkswagen emissions scandal, know that the Range Rover meets all requirements thanks to a urea solution in place to convert nitrogen-oxide emissions into pure nitrogen.

Drive it, and it doesn't take long to understand why this powertrain is so popular on the Continent. The torque-rich V-6 pulls strongly from low rpm, making this engine a natural companion to this big brute's solid, stoic personality. The long-travel throttle pedal means it is easy to make small adjustments as you tap into the strong torque band, which produces the full 443 lb-ft from as early as 1,750 rpm. The eight-speed automatic shifts smoothly and quickly, and the Range Rover is quite responsive to sudden throttle changes. Ask for a kickdown and the transmission ably abides, and the diesel engine pulls the 4,730-pound SUV along with authority. It's not quite as sonorous as the gasoline V-6 also offered in the Range Rover Sport, but that's a trade-off we're more than willing to make for the diesel's smooth performance and much-improved fuel economy.

Electricity is more of a novelty

The BMW is a bit more innovative, not to mention more complex. As the company's second-ever plug-in hybrid after the AUTOMOBILE All-Star-winning i8 sports car, the X5 eDrive is packed with advanced electrification technology. A 2.0-liter, gasoline turbo-four engine combines with an electric motor to provide a healthy total system output of 308 hp and 332 lb-ft. Operating in standard hybrid mode, the BMW offers a 4-mpg boost in EPA combined numbers compared to the six-cylinder gasoline X5, though its 24 mpg combined actually falls short of the 26 mpg that BMW's own X5 diesel provides.

The X5 eDrive's real kicker, then, is the electric plug found on the driver's side front fender. When hooked up to a Level 1 or Level 2 charger, it charges a beefed-up battery pack that allows the X5 to operate on all-electric power up to 75 mph. Driving the X5 in electric mode is a disconcerting experience, and that's not meant as a bad thing. With utter silence and instantaneous torque from the electric motor, the sizable X5 shrinks around you as you maneuver city streets without a whisper from gas engine. Even though it weighs 5,220 pounds, the X5 takes on the character of an urban runabout when it needs to. It's almost like driving a bigger, raised Nissan Leaf with a much nicer interior.

We say "almost" because the silence of all-electric driving is noticeably short-lived. The EPA rates the X5 for 14 miles of electric range on a full charge, and that estimate was mostly borne out in our driving, except in colder temperatures when it would more often yield about 12 miles. Once you run out of juice, the X5 runs in normal hybrid mode, trading off power between the gasoline four-cylinder and the electric motor like a conventional parallel hybrid. The transitions are mostly seamless, and the combined power of the drivetrain is more than sufficient.

MPG in the real world

Despite all the widely disparate approaches to fuel efficiency, real-world results couldn't have been closer after we spent 600 miles driving both SUVs in a variety of conditions. The BMW slightly edged out the Range Rover, at 21.8 mpg to the Brit's 21.3 mpg.

Of course, those numbers come with plenty of caveats. The Range Rover might have done better if we had spent more time on the highway, while more city driving would have favored the BMW. The amount of fuel you use in the X5 is also hugely dependent on how often you plug it in. We can imagine some owners going weeks between fill-ups if the X5 plugs in at home and at work, especially if it's mostly used for short trips.

When it comes down to it, the crucial difference between the two is that the BMW requires more of a lifestyle adjustment than the Range Rover does. The X5's myriad energy display graphics and adjustable charging settings are great for eco-conscious early adopters. Like Chevrolet Volt owners, those who are willing to spend the extra time to hook up a home charging adapter, look for public charging stations, and generally stay aware of X5's state of charge will be able to maximize its use of electricity in exchange for their vigilance.

With the Range Rover, the addition of a more efficient powertrain requires almost no compromise from your typical luxury SUV buyer. Not only does it cost only $1,500 extra compared to a gasoline-powered Range Rover (the BMW hybrid is $5,100 more than its gasoline equivalent), the diesel engine's quiet, refined, and torquey character doesn't present any clear drawbacks. The only adjustment you'll have to make is remembering to grab a different pump at the gas station. Easy as signing up for Netflix, no?

2016 BMW X5 xDrive40e Specifications

On Sale: Now
Price: $63,095/$73,770 (base/as tested)
Engine: 2.0L turbo DOHC 16-valve I-4/240 hp @ 5,000-6,500 rpm, 260 lb-ft @ 1,250-4,800 rpm plus electric motor; total system power 308 hp, 332 lb-ft
Transmission: 8-speed automatic
Layout: 4-door, 5-passenger, front-engine, AWD SUV
EPA Mileage: 24 mpg combined (56 mpge combined)
L x W x H: 192.4 x 86.0 x 69.4 in
Wheelbase: 115.5 in
Weight: 5,220 lb
0-60 MPH: 6.5 sec
Top Speed: 130 mph

2016 Range Rover Sport HSE Td6 Specifications

On Sale: Now
Price: $72,945/$84,260 (base/as tested)
Engine: 3.0L turbodiesel DOHC 24-valve V-6/254 hp @ 4,000 rpm, 443 lb-ft @ 1,750 rpm
Transmission: 8-speed automatic
Layout: 4-door, 5-passenger, front-engine, 4WD SUV
EPA Mileage: 25 mpg combined
L x W x H: 191.2 x 87.4 x 70.1
Wheelbase: 115.1 in
Weight: 4,730 lb
0-60 MPH: 7.1 sec
Top Speed: 130 mph
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