Gasoline engines have, by no means, reached the end of the line in terms of improving efficiency. And that's going to put more pressure on other technologies to prove their worth to consumers.
Advances like direct fuel injection, sophisticated variable valve timing, turbocharging and more advanced transmissions -- among lots and lots of other things -- are combining to get more miles out of each gallon of gasoline without having to rely on expensive electric drive.
Added to all this will be some technologies culled from hybrid cars, but used in smaller doses for reduced costs. Case in point: the 2013 Chevrolet Malibu Eco which uses a kind of "mild hybrid" system to boost fuel economy.
Tesla Motors unveiled a new SUV that the automaker plans to put into production by 2014.
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