Luxury SUV brands like Range Rover ushering in plug-in hybrid power

The large, plush Range Rover has been a favorite SUV for everyone from the British royal family to American sports and entertainment stars. But one of its attributes has never been fuel efficiency. Two things in abundance will put a damper on miles per gallon: power and weight.

But a new Range Rover model is a little different. The P400e plugs in.

No, it's not a pure electric, but it's a plug-in hybrid electric vehicle, or PHEV. Charge up the battery, and it can go 20 to 25 miles without the gasoline engine coming on. That doesn't sound like much, but it's plenty for short trips, and it helps the big "Rangie" in two ways.

First, with its official EPA numbers. The big supercharged V8 model currently gets a so-so 18 mpg combined on the official EPA fuel economy cycle. But while official testing has not been done on the P400e, it has the potential to do very well in what's known as "MPGe," where the miles driven under battery power are factored in. Other large PHEVs have been able to post mpg numbers that are double or even triple the ones that their non-PHEV equivalent can get. For example, the Volvo XC90 T8 is a PHEV, and has an EPA MPGe rating of 58. The non-PHEV T6 version has a combined number of 22.

Okay, people who spend $108,000 for a luxury SUV (the price tag for the Range Rover P400e shown) probably don't sweat the price of gas, even when it jumps up. But they may want to be seen as doing what they can for the environment by reducing consumption. Also, in some crowded cities around the world there's talk of banning combustion engine use. A PHEV in electric mode would get an exemption.

And that's why other luxury SUV brands are going the same way. Mercedes-Benz will soon have PHEV versions of many of its SUV models, starting with the new GLC350e. And even ultra-luxury brand Bentley is about to introduce a plug-in hybrid version of its Bentayga SUV. The times, they are a-changin', as the saying goes.

Another plus for a PHEV vehicle running on electric power is that it's very quiet when in EV mode. The Range Rover is already known for its interior quiet; when running on batteries, the cabin is downright silent.

Of course, when this Range Rover P400e's four cylinder engine is needed, it does make a bit of a ruckus that you don't hear in the conventional V8 model. The engineers at Land Rover did the best job they could quieting down the Ingenium engine, as they call it, but it's still fairly loud at full throttle.

But that may be a small price to pay for the other side of this combination power train, which is the ability at times to glide along electrically, gas-free. And perhaps almost as importantly for some buyers, guilt-free.