“The point where a car can actually go after a mass-market audience is when the pricing starts making sense on paper,” said Jesse Toprak, vice president for market intelligence at TrueCar. “If they want these technologies to be mainstream, pricing still needs to come down.”

The Prius and Lincoln MKZ are likely to produce overall savings within two years versus similar-size gas-powered cars from the same brand, but other hybrids, despite ratings 8 to 12 miles per gallon better than conventional models, will cost more to buy and drive for at least five years.

The data assumes an average of 15,000 miles driven a year and a gas price of just under $4 a gallon.

If gas cost $5 a gallon, the TrueCar data estimates that the payback period for a hybrid Ford Fusion over the conventional Fusion would be six and a half years, compared with eight and a half years at $4. At $6 a gallon, the hybrid Toyota Camry, Hyundai Sonata and Kia Optima are likely to generate savings within four years.

So why do some buyers pay more for advanced technology that might not save them money? Many never do the math, analysts say, or they tend to overestimate how much the added miles per gallon translate into actual monetary savings. Some view the higher mileage as better for resale value, hoping to come out better on the back end.

“The price of the vehicle, you only pay it once and then soon forget about it,” Mr. Toprak said.

Others clearly view saving fuel and doing something better for the environment as their ultimate goals, regardless of cost. The Prius, for example, became a success in part because drivers wanted to drive — and be seen driving — a hybrid.