When most people hear “hybrid,” they picture a small car (think: Toyota Prius). However, small cars already get pretty good mileage. You’ll get bigger gains in fuel economy with a bigger vehicle, such as the Lexus GS450h.

The GS is all-new after a lengthy run. It has been so long since a redesign, in fact, that until three years ago, dashboard cassette decks were part of the standard equipment. The new GS is lower, wider, and much more aggressive looking. Plus, it’s capable of startling mileage for its size and class.

Consider: The gasoline-powered version, the GS350, has an EPA estimate of 19 city and 28 highway. Step up to the GS450h hybrid and the highway fuel economy goes up by 6 miles per gallon, but there’s a whopping 10-mpg improvement in the city estimate. It conserves fuel by shutting off at stoplights and benefits from a purely electric mode that covers a lot of city driving. Use a light throttle foot pulling away from a stop, and you can get up to 40 miles per hour before the gasoline engine engages. That’s 10 to 15 mph faster than most hybrids achieve before they start burning gas.

But all these benefits come with a worrisome price tag increase. The gap between the gasoline and hybrid versions of the GS is a startling $12,200. That’s money you won’t get back from savings at the pump anytime soon. (The U.S. Department of Energy has a calculator at fueleconomy.gov that illustrates it will take Lexus 3.8 years to pay you back for difference in what you’ll spend on the hybrid upgrade.) 

That shoots down one of the big rationales many hybrid buyers use for the added technology expense. So what else does the GS450h have that makes it worth consideration, even at the added cost?

It may seem contradictory, but the GS450h is actually more powerful than the gasoline-powered ES350; it packs 32 more horses. And the list of standard features is much more extensive, featuring items that are extra-cost luxury options in the gasoline model. Of course, it has a menu of extra-cost options of its own, which is how the as-tested price ended up more than $10,000 higher than even the hybrid’s base price.

The GS450h is for the driver who doesn’t want to compromise speed or luxury, and wants to do his or her part for the planet, both in terms of consumption and emissions, without worrying about a return on the financial investment.

If you don’t mind dropping a little extra green in the name of going green, this is the car for you.

Michael Hagerty is an automotive publisher and editor who has been talking cars on the air, in print, and online for more than 15 years.