Bob Brooks of Consumer Guide reports on one technology, the hydrogen-boosted engine, as a possible future consumer demand. This gas engine injects hydrogen in the regular air/fuel mix of a normal gasoline powertrain. Fuel economy is increased by as much as 30-percent. Other advantages include very little NOx emissions, and low installation costs. The biggest issue, of course, is the lack of hydrogen-fueling stations.
The technology was developed by researchers at the Massachusetts Institute of Technology, with ArvinMeritor and IAV currently developing it. An SUV is being equipped with the engine for trials, with the first production vehicle planned for delivery by 2010.
More details on the hydrogen-boosted system can be found at the link.
[Sources: Consumer Guide, ArvinMeritor]