It happens every time. Gas prices go up sharply, and new car buyers suddenly decide that gas mileage is important--and shop accordingly.

With gas around $4 a gallon in many parts of the country, what would you trade for higher miles per gallon?

Would you pay more? Would you buy a smaller car than your current one?

How about giving up features you'd hoped to have? And what about safety?

Everyone wants more mileage

Six weeks ago, Consumer Reports surveyed 1,750 car owners. Although their cars were now eight years old on average, less than one-fifth of them planned to buy a car in the next year. Of that pool of buyers, six out of 10 were planning to buy used cars rather than new.

Honda Dealership

Honda Dealership

When they do finally buy, almost two-thirds of respondents expect their next car to have better gas mileage--and virtually all the rest expected fuel economy to stay the same.

How high do they expect it to go? On average, the respondents said their new car would return 29 miles per gallon. But older drivers, lower-income buyers, and women expected higher fuel economy, and favored sedans and small cars over larger cars and crossover utility vehicles.

Remarkably, more than 10 percent of respondents said they expected their next car to deliver 40 mpg or higher.

40 mpg: still rare

That's a high bar indeed. For the 2011 model year, only four cars on the U.S. market deliver EPA combined mileage of 40 mpg or more, all hybrids: the Honda Civic Hybrid, Honda Insight, Lexus CT 200h, and Toyota Prius. For 2012, the Toyota Prius V wagon is likely to join that list.

2011 Toyota Prius

2011 Toyota Prius

There are also three plug-ins, the 2011 Chevrolet Volt, 2011 Nissan Leaf, and the 2011 Smart ForTwo Electric Drive. (There's also the $109,000 Tesla Roadster, but that's hardly a mass-market vehicle.)

More than half the respondents (58 percent) say they will pay more to get a car with higher gas mileage. Just under half (47 percent) would compromise on "size or capacity," and the same (44 percent) for giving up "amenities or comfort."

Safety is paramount

Acceleration is still seemingly important. Only 27 percent would sacrifice performance, and a mere 11 percent were willing to compromise on safety.

That last question is a ringer of sorts, though. Virtually any new car now comes with six or more airbags, traction control, anti-lock brakes, and a host of other electronic safety gear. Crash-test results from the NHTSA and IIHS are widely publicized, and any maker who doesn't score one of the top two ratings will modify future models to ensure they do.

Jeff Bartlett of Consumer Reports points out, however, that in general the most recently redesigned new cars do better on crash tests than models toward the end of their lifespan. So a car that's new for 2012 is likely to be safer than one first introduced in 2008.

Also, he says, for the six out of 10 buyers whose next car will be a used model, they should check safety ratings carefully.

2011 Chevrolet Equinox LTZ

2011 Chevrolet Equinox LTZ

The survey group is slowly moving away from more-economical sedans and toward small and midsize crossover utility vehicles, which are less fuel efficient.

As the report noted, "Men prefer pickup trucks by a wide margin, while women lead small sport-utility vehicle interest."

[Consumer Reports]

+++++++++++

Follow GreenCarReports on Facebook and Twitter.