The Auto Industry Is Pushing All Three, but Americans Aren't SureThe next time you're filling the tank and glare at the spinning numbers showing how much gas is costing, your mind might just slip away to visions of a perfect world.

In that perfect world, cars would be clean running and fuel would be cheap. And we're not talking about those battery-powered cars or hybrids that only get great mileage when you drive like an 80-year-old grandmother. After all, Americans like big engines and powerful acceleration, so the perfect car would have some get-up-and-go when you need it.

Now wake up because that perfect world of a clean, cheap and high-performance engine is almost here. In fact it is here, but you have to go to Europe to see it in action. It's diesel. And, for a couple of thousand dollars more, these engines get the same amount of horsepower with 30-percent better fuel economy and arguably lower emissions.

The European continent has fallen head over heels for diesel engines. In many areas, gasoline can run $5 to $6 per gallon, pushing consumers to look for other options. In fact, some 50 percent of new cars sold in Europe these days are diesels, up from 17 percent in 1992.

The only downside to vehicles with these engines is their price. They tend to be a couple thousand dollars more expensive than gasoline engines because they are more highly engineered, use more advanced technology and often require a turbocharger that kicks in to give added boost for acceleration.

The cost factor, combined with the relative affordability of gasoline in the U.S., has kept enthusiasm for diesels low. Furthermore, earlier forays into diesel technology in the 1980s were bungled by automakers leaving a sour aftereffect that lingers on.

Analysts have long predicted that diesels will make their move onto American soil when gasoline prices rise to prohibitive levels. And with the nation now shelling out more than $3 per gallon or more, the feeling is that time is now.