If you're in the market for a big car or truck, you definitely want this proven, gas-saving technology.

It seamlessly deactivates some of the cylinders in your engine when you're cruising at highway speeds and don't need full power.

Your V6 or V8 engine has all the horsepower you need when taking off from stoplights or accelerating onto a freeway, but it will get 10% or so better mileage when it only needs to run on four cylinders.

Honda, for example, is offering a cylinder deactivation system on its Accord midsize cars for the first time this year. An earlier version has been on the Odyssey minivan since the 2005 model year and the two-wheel drive Pilot SUV since the 2006 model year.

A 2008 Accord with a V6 engine has 268 horsepower, considerably more than the 190 h.p. you'd get from the 2.4-liter four-cylinder engine. But because of the cylinder deactivation system, you won't pay a big penalty in fuel economy.

You'll only get about 2 miles per gallon less than with the smaller four-cylinder engine in both city and highway driving. And 29 m.p.g. on the highway is very good for a midsize sedan with a V6.

Click here for more fuel saving tips.

Or go here to read more about the Accord, which we think is one of the best midsize cars for 2008.