These days, everyone's grumbling about the skyrocketing cost of gas. And while it might be great to trade in your minivan for a scooter, it's not exactly the most practical option for a family of six. So what's the solution?

Revetec, a company from Australia's Gold Coast, may have a bright idea for beleaguered drivers everywhere – and it's got nothing to do with the size of your car: it's all about the engine.

The new engine from Revetec is half the size and weight of a traditional engine, and has 50 percent fewer emissions. Best of all? The engine can actually double your fuel economy. We know it sounds like the sort of pipe dream eco-entrepreneurs have been spouting for years, but the company has a working prototype that's proven that their state-of-the-art engineering techniques do exactly what they claim.

It's still not clear when Revetec's new engine will be commercially available, but we've got a feeling that, in the absence of a time machine, any engine that can let you fill up your gas tank for $20 is sure to be a hit.

By Kathryn Hawkins