The real alternative is a fully continuoes gearbox (Score 1)

The best alternative I have ever seen to improve fuel economics on vehicles is this new Flagear fully continuous gearbox: http://flagear.fladby.com/

The gearbox is computer controlled to keep the ratio between engine speed (rpm) and the effect needed optimally at all times, thereby keeping the engine speed as low as possible which in general results in up to 50-80% less consumption of fuel.

The environmental benefits will be huge. 50-80% reduction of the fuel consumption will fulfill the Kyoto- agreement 5-7 times.