What is the Break-Even Point on Hybrid Gas Savings?

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What's the break-even point when you buy a hybrid? How long do you have to own a hybrid, and how far must you drive one, before the money you save on fuel offsets the additional cost?

A new website from the U.S. Department of Energy has some surprising answers to those questions.

"Hybrids have moved from the early-adopter stage to the mainstream," said Bo Saulsbury, a researcher at Oak Ridge National Laboratory, and one of the people who created the comparison website. "We thought it was important to give people a tool to figure out if they're worth the cost. A hybrid won't always pay for itself, but some will."

The website, fueleconomy.gov, shows how much a hybrid adds to the sticker price vs. a comparably equipped model, how much money it will save every year, and how long it takes to repay the initial cost.

The higher gasoline costs go, the quicker the payback for all hybrids:

The Buick LaCrosse and Lincoln MKZ hybrids pay for themselves in the first year. They have the same MSRP and better fuel efficiency than V-6 versions of the same cars.

The Cadillac Escalade hybrid, which was initially belittled for its 21 mpg combined city/highway fuel economy rating, pays for itself in a mere 2.1 years.

The much-less-expensive Kia Optima hybrid won't break even for 4.9 years, according to the website. That's because the Escalade's 6-mpg fuel economy improvement from the base model's 15 mpg is a bigger deal percentage-wise than the Optima's jump from 28 mpg to 37 mpg.

The Kia's $2,500 cost increase is also a much greater proportion of its sticker price than the Escalade's $2,175 rise.

"Sometimes, the most bang for the buck is in big vehicles," Saulsbury said.

The website calculator compares hybrids with their conventionally powered counterparts.

For instance, it compares the fuel cost for a Honda Civic to a Honda Civic EX-L, the most similarly equipped non-hybrid Honda builds.

Not every comparison is that exact -- the Honda CR-Z is compared to a Honda Fit, for instance -- but the DOE found the closest match possible for 18 popular hybrids.

Go to the website tab labeled "Advanced fuels and vehicles." From that pull-down menu, click on "Hybrids can save you money."

The website doesn't make projections for hybrids if a brand doesn't offer an equivalent conventional model. That means there's no information on the Lexus CT 200h, because the hybrid is the only hatchback and only compact in Lexus' lineup.

The site also omits hybrids for which the payback period is more than six years. Plug-in hybrids and electric vehicles aren't on the list, but may be added as they become more common.

The big winners in terms of quick payback seem to be vehicles that keep costs low by limiting the hybrid system's power and luxury models that already cost so much adding the hybrid doesn't have much impact on the original price.

You can change the number of miles driven, percentage of highway vs. city driving and fuel costs to reflect your driving habits, or how much you expect fuel prices to rise.

The DOE plans to update the site as new models become available and to reflect changing fuel prices.