While the Chevrolet Volt is a hybrid that is still not available for purchase, there are ways of converting existing cars to be VERY high mileage hybrids. Some can get as much as 100 miles per gallon. Essentially, there are companies selling a retrofit kit for existing hybrids like the Toyota Prius and Ford Escape. The kits can run from $5000 up to $35,000 but mileage can average around $100 per gallon. Depending on your vehicle usage this could be a fantastic upgrade!