Half of all American vacationers on the road this year are driving gas-guzzling SUVs and pickup trucks, according to a new survey on driving habits from research firm MarketFacts. These bigger vehicles burn high amounts of fuel, which not only puts a dent in drivers' wallets, but also increases the country's dependence on foreign oil. Ironically, the MarketFacts study shows that fuel economy is an important issue for SUV and pickup drivers.

According to automotive experts, standard gasoline engines can't efficiently handle the weight of the larger - and very popular - SUVs and pickup trucks. There is an alternative, however, for drivers of big vehicles to consider: diesel engines.

Diesel engines like the Power Stroke® Diesel in Ford F-Series Super Duty pickups are specifically made to provide better mileage -30 percent in most cases - and have more pulling power than gas engines, which is why they are especially popular among those hauling camping gear or towing boats, RVs and horse trailers.

"People love big trucks for a lot of great reasons, but running a gas engine in them is like trying to heat a hotel with a small home furnace. You're going to burn way too much fuel and you still won't get the power you really need," said Patrick Charbonneau, chief technical officer, Engine Group, International Truck and Engine Corporation. "Diesel engines produce more power than gasoline engines because diesel fuel itself has more energy. And today's diesel engines are electronically controlled to boost performance and fuel efficiency."