Land Rover, which is owned by India's Tata Motors, is seeing surging demand for its vehicles. It sold a record 62,141 units in the U.S. in the first 11 months of this year, up 36% from 2014. Like other makers of large, heavy and expensive SUVs, it has benefited recently from lower gasoline prices and a shift in consumer preferences toward taller vehicles. 

Even so, makers of this fuel-thirsty vehicles must be worried about what happens to sales if and when gas prices rise again. They may also want to entice buyers who aren't crazy about consuming lots of fossil fuel.

Land Rover's regular Range Rover Sport yields 17 MPG city, 23 MPG highway, for a combined 19 MPG. Depending on which version of the Range Rover we are talking about, it tips the scale at a curb weight of 4,661 pounds. How does one improve on this hefty fuel consumption without adding significant weight to this already heavy vehicle?

One approach is to add electric motors and batteries, or hybrid electronics. That adds significant weight, though, which will strain the suspension, tires, wheels and other body components. It also puts more wear on the road -- not to speak of adding tens of thousands of dollars to the price of the car.

Case in point: The all-electric Tesla Model X has a curb weight of 5,441 pounds, or 780 pounds more than the Range Rover Sport. Is there a better way that would reduce the harm done to our roads resulting from heavy vehicles?

Range Rover has taken a different approach for the 2016 model year Range Rover: diesel. By offering a diesel engine, it can show at least 32% improved fuel economy while only adding 44 pounds. Yes, you read that right: 44 pounds. Not 780 pounds.

Even so, the Range Rover is able to tow 7,761 pounds. That's more than 50% more than the Tesla Model X, which can tow only 5,000 pounds.

But what about power, you ask? Won't a 32% improvement in fuel economy result in a weaker engine? Actually, the diesel engine yields 443 pound feet of torque, up from 332 in the Range Rover's gasoline engine. That's a 33% increase!

Wait a minute! I get 33% more torque and 32% more fuel economy, without any significant weight penalty? Surely that must be an expensive technology!

Well, it's not. Range Rover charges only $1,500 for this miracle cure. It estimates that the average U..S driver will save $450 per year over the base 3-liter gasoline model. Considering that diesel cars also tend to have a higher used-car value, that makes the matter an obvious economic proposition.

So the diesel makes more torque, consumes less fuel, doesn't add much of a weight penalty, and is only $1,500 extra. Surely the hitch is in the driving experience, right?

Range Rover claims that it conducted a blind test on 400 would-be customers. They got to drive the Range Rover diesel but weren't told it was a diesel. Not a single person figured it out!

I obviously knew it was a diesel when I drove it. That said, I drove it anywhere from 80 mph on the freeway to challenging off-roading, and it was the quietest experience imaginable. I have driven the latest diesels from Mercedes and BMW, and this was the best driving experience to date.

The Range Rover diesel is simply amazingly quiet, even at high speeds. I can't recall a quieter car that I've ever driven. There is no engine noise, and the least amount of wind noise imaginable. I could whisper and be heard with ease. It's like sitting in an underground bunker.

Steering and handling are extremely tight, and the view out the windshield is majestic. This "command" seating position works very well. I achieved between 25 MPG and 26 MPG on one long drive, which was driven at an average of 75 MPH and mostly uphill.

It's very clear what the two drawbacks of the Range Rover are. First, the infotainment system. It lacks three things:

    Alphabet's Android Auto.

    Apple CarPlay.

    4G LTE (It has only 3G).

    It's hard to say when these three major features might arrive. In the meantime, the system at least differentiates itself compared to BMW, Mercedes, Audi and Lexus by being a touchscreen system, which does not take up space on the center console for a knob with a variety of buttons around it.

    The problem is that other competitors will soon exceed Range Rover in terms of their infotainment capabilities. The all-new Audi Q7 that's arriving in U.S. dealerships in January 2016 has Android Auto, Apple CarPlay and 4G LTE. The Volvo XC90 has Apple CarPlay and will get a software update to Android Auto in 2016.

    The second drawback with the Range Rover diesel is the base price of the vehicle itself. Here are the four versions you can buy:

    Range Rover Sport diesel: $67,445

    Range Rover Sport HSE diesel: $72,445

    Range Rover diesel, full size: $87,445

    Range Rover HSE diesel, full size: $94,445

    Basically, the full-size Range Rover costs anywhere from $20,000 to $22,000 more than the regular Range Rover Sport. The main differences are that the Sport feels a bit stiffer, including the driver's seat, and has less room for the rear seat passengers and for luggage compared to the full-size Range Rover.

    However, for most people, I think the Sport version will be plenty. Nicely equipped, you should consider the HSE version that starts at $72,445.

    That's expensive when you consider that a Jeep Grand Cherokee diesel 4x4 in its highest trim -- "Summit" -- starts at $55,490. Also, the new Volvo XC90 plug-in hybrid starts at just under $70,000 and will offer you a car with many advantages over the Range Rover, including a useful third row.

    From that perspective, the Range Rover models are expensive. When compared to the "next step up," it's a bargain though. That next step up is the Mercedes G550, which is arguably the king of SUVs, but it costs $120,000, and yields 12 MPG city, 15 MPG highway as it's not available with a diesel in the U.S.

    Driving the Range Rover diesel is an amazing experience in powertrain refinement and a quiet luxury cabin, even at very high speeds. When you combine that with Range Rover's proven off-road superiority, it makes for a very high grade. With the caveats of not having Android Auto, Apple CarPlay and 4G LTE, I think it's best in class.

    Hey, just remember this: The Range Rover diesel is a luxury SUV that's rated at 29 MPG without any compromises in comfort or capabilities.

    This article is commentary by an independent contributor. At the time of submitting this article for publication, the author was short TSLA and long GOOG, GOOGL and AAPL. However, positions can change at any time. Jaguar Land Rover paid for airfare, lodging and meals at a vehicle launch event.