We've espoused about the need for hybrids to better incorporate geographical data to maximize efficiency. Now researchers at the University of Riverside in California back us up, saying that they expect the range of electric cars could be increased by as much as 10 percent just by feeding into the car data about traffic in real-time, hills, and road surfaces, plus passenger and cargo weight.

With a grant from the California Energy Commission, UC-Riverside's Center for Environmental Research and Technology researchers are applying earlier data to electric cars. This data set from senior researchers at the university found that the fuel efficiency of fossil-fuel powered cars could be increased by 5 percent to 15 percent, based on several small studies, by choosing the most efficient route given current road and traffic conditions and giving the driver feedback about how to be more efficient. Large-scale programs in Asia and Europe have seen 20-percent improvements in fuel efficiency through such strategies.

The effect may be even greater for internal combustion cars, as any energy used to accelerate in traffic or city environments or to climb a hill is just wasted when you apply the brakes to slow back down. There is no getting the spent fuel back. On the other hand, using electricity provides the opportunity to recapture much of this energy through regenerative braking, and the benefits of this approach to saving energy could reduce range anxiety. But, perhaps hybrids could provide the most benefit if the cars were empowered to choose between their electric and gas source for a given condition. (Read: "Conquering hills may be the next hybrid car frontier.")

Fully realizing this potential would require drivers to enter their destinations into a navigation system, allowing the car to integrate route, traffic, and topographical data to choose the most-efficient route—ideally one best suited to the specific car. The car would also need to give feedback, essentially training the driver on how to be more efficient. This is done to varying degrees in several current cars, most often hybrids and EVs.

As early advocates of this approach to saving gas, we'll eagerly await the researchers' further findings and better yet, the inevitable in-car applications. For energy savings now, some portable GPS devices, such as recent Garmin navigators, include a choice for the thriftiest routing.

Learn how you can save fuel today in our guide to fuel economy.