Plug-in SUVs growing in popularity, variety

There was a time when a hybrid SUV seemed like an oxymoron. But back in 2006, the first Lexus RX Hybrid was introduced. Now, there's a fourth-generation RX450h hybrid, and it's available as the L model with a third row seat. It still does very well on the EPA mileage cycle, with a combined number of 30. The standard RX450h with two rows of seats starts at $46,750.

But there's another kind of hybrid SUV these days: the plug-in type, or PHEV. Charge up the battery of the Porsche Cayenne e-hybrid, and you can drive about 13 miles on the electric motor alone. But of course, this is a Porsche, so there's a total of 455 horsepower when the electric and gasoline drives are combined. And under the right conditions, the Cayenne e-hybrid can do up to 83 miles per hour on electricity. Base price for this Porsche PHEV SUV is about $80,000.

Plugging in for EV driving miles is what the flagship model of the new Lincoln Aviator is about. The Grand Touring version has a combined output of nearly 500 horsepower, and the ability to go up to 21 miles on electric power. The top of the line Lincoln SUV carries a base price of $68,800.

For a wide variety of PHEV SUVs, look to Volvo, which is busy electrifying its whole lineup. The T8 version of the XC60 model is good for up to 20 miles of gas-free driving. There is also T8 PHEV version of the larger XC90, and the smaller XC40 is produced as a PHEV, but not for the US market. (There will be a pure electric XC40 coming in about a year.)

The plug-in range of these vehicles might not seem that great, at anywhere from about 12 to about 20 miles. But the idea is that a driver can use the battery power for driving in cities, where emissions are a bigger issue, but then have a conventional engine for highway travel. The other thing PHEVs can do is get buyers used to the idea of plugging a car in to recharge.

And it's not just high-end models. The Mitsubishi Outlander PHEV is a plug-in as well, and is helping Mitsubishi regain its traction in the U.S. market, as buyers look for a combination of fuel savings and utility. The company says the vehicle is good for up to 22 miles of electric driving. The base price is a bit on the steep side for a small SUV at $36,295.

The trend continues with Toyota's hot-selling RAV4 model. Already offered as a hybrid, Toyota recently announced that a plug-in version is on the way. Like the PHEV version of the Toyota Prius, the new RAV4 will carry the sub-model name "Prime." The vehicle will have an electric range of 39 miles, according to Toyota, when it arrives in showrooms next summer.

So while SUVs have long been associated with lackluster fuel efficiency, things are changing. Hybrid and now plug-in hybrid models are helping drivers carry people and things, without always burning gasoline.