With several manufacturers offering increased-economy versions of their regular vehicles these days, you might be tempted to buy them as a way of saving some money on gas.

Improved aerodynamic fittings, low rolling-resistance tires and altered gear ratios are all used to eke out a few extra MPG from an otherwise standard model. But are these vehicles worth the extra few hundred dollars over a regular model?

Consumer Reports isn't so sure, after testing three the most popular high-mpg models: The 2012 Ford Focus SFE, 2012 Chevrolet Cruze Eco, and 2012 Honda Civic HF.

Each car features a series of detail changes over the regular Focus, Cruze and Civic. Common to all three is a small spoiler on the trunk, and each also uses low rolling-resistance tires. The Civic and Focus also feature flat wheel designs--alloy for the Civic, plastic trims over steel wheels for the Focus--to cut aerodynamic drag.

All three cars were equipped with automatic transmission, though Consumer Reports (CR) notes that a manual is standard on the Cruze, albeit less popular.

Read our reviews of the 2012 Chevrolet Cruze, 2012 Ford Focus and 2012 Honda Civic

The EPA has rated the Civic HF at 33 mpg combined, a figure the Focus SFE shares. The Cruze Eco is rated at 31 combined.

In testing the Civic HF managed 33 combined, 3 mpg above the test results for a Civic LX. The Focus managed 31 mpg overall, again 3 mpg better than a non-SFE Focus. Least impressive was the Cruze Eco, which achieved 27 mpg overall, only 1 mpg better than CR's results for a regular Cruze.

Most impressive overall was the Civic, that beat its 41 mpg EPA highway rating by managing 49 mpg--that's hybrid territory--though the average was brought down by city mileage of 21 mpg, 8 mpg down on that of EPA testing.

With MSRPs of between $500 and $800 more than the models on which they're based though, it puts a question mark over whether they're really worth the extra--at least from a financial perspective.

In a worst-case scenario, CR points out that you'd need to own one model--we suspect the Cruze, based on list price differences and tiny economy improvements--for 38 years before the savings paid off.

CR highlights that alternatives like the Mazda 3 SkyActiv and Toyota Corolla may achieve similar mileage figures, without having to spend extra on special packages.

We'd also be tempted to add that if you plan on keeping your car for a reasonable length of time, you'd be better of spending a little more and getting an even more efficient hybrid vehicle.

Not only will the greater fuel efficiency start saving you money sooner, but you'll be reducing tailpipe emissions, too.


Follow GreenCarReports on Facebook and Twitter.