The SUVs of the future isn't quite the SUV of today

Gas engines, too, can be made far more efficient with existing technology, Hwang said. Recent improvements include:
> Lightweight materialsand more aerodynamic designs.
> Direct-injection turbo-chargers, like Ford's EcoBoost, which allow vehicles (like the F150 pictured here) to produce as much power with fewer cylinders, less friction and less fuel demand.
> Start-stop systems that automatically switch idling engines off, and restart them instantly.
> Cool-boosted exhaust gas recirculation, which helps deliver more oxygen-rich fuel by lowering its temperature before fuel-injection.

"I don't really expect that when you go to the showroom that you're going to be faced with vehicles that are any different looking," NRDC's Hwang said. "You'll still see SUVS, minivans, pickups, cars. But the drivetrains will be better… Unless you're a real gearhead you're not really going to notice the difference."

The EPA predicts hybrids will account for as little as 25% of the market in 2025, or as much as 65%, depending on how aggressively car manufacturers take advantage of credits and incentives, and how much consumer demand there is. Electric vehicles will hold no more than 10% of the market, leaving a healthy slice for traditional gas engines with more advanced features.

Hwang's prediction differs slightly. In 2025, he expects about one-third of vehicles for sale will be hybrids and 10-15% electric, leaving more than half the cars on the average lot powered by gas engines.