E85 factor
Shoppers will also confront such issues as vehicles that can run on both regular gasoline and ethanol-based E85 fuel, which is a mixture of 85 percent ethanol -- made from agricultural products like corn -- and 15 percent gasoline. Drivers concerned about fuel economy will soon learn that while ethanol is cheaper per gallon it also gets fewer miles per gallon than gasoline.

Consider the Chevrolet Monte Carlo, which under the new EPA test procedures is rated at combined mileage of 22 mpg. When run on ethanol, which packs less energy in a gallon, it's rated at just 17 mpg in combined city-highway driving. But depending on the cost of ethanol fuel -- which is supported by significant tax breaks -- a driver could still save money over running on straight gasoline. The biggest drawback, however, is that E85 fuel is unavailable in many parts of the country. For now, the Midwest is where E85 fuel is most prevalent.

Then there are the new, cleaner-burning, quieter diesel vehicles that are just now coming to market. Using new-formula diesel fuel with less sulfur, these vehicles promise higher fuel mileage than their gasoline counterparts. The leader of the class is the pricey Mercedes-Benz E320 Bluetec, which is rated under the new EPA rules at 26 mpg in combined city-highway driving. That compares with the gasoline-powered E350, which is rated at 19 mpg in combined driving.

The downside is that the diesel option can add significant cost to a vehicle and the cost of diesel fuel in some parts of the country is comparable or greater than a gallon of gasoline, negating some of the fuel mileage benefits.

What to do
So what's a buyer to do?

First, make an honest assessment of what you need in your next vehicle in terms of passenger capacity, size and price. Then consider your budget for fuel, taking into account that you're likely to have your next vehicle for five or more years. While no one has a crystal ball to know what gas will cost over that period, it's a safe bet that prices will not be returning to $2 a gallon. So plan accordingly.

While your mileage and cost will vary, it's a place to start when deciding which new vehicle will best suit your mileage needs.

Terry Jackson is a freelance writer in Florida who has authored six automotive books. He is former editor in chief of AMI Auto World Magazine and NOPI Street Performance Compact. He has also written for Automobile, Road & Track and AutoWeek. He races a vintage Mustang in SCCA competition and evaluates as many as 100 new cars each year.