Commercial diesel may cost a little more per gallon than gasoline, but ask any diesel owner, and they'll tell you that you get far more fuel economy for the price. Whether you're looking for a GMC/Chevy Duramax, a Dodge Cummins or a Ford Powerstroke vehicle, follow these tips from diesel experts to find a fuel-efficient truck that still packs plenty of power under its hood. 

Buy the Right Truck for Your Job
"What do you need your truck to do?" That's the question Meridian Idaho based Gem State Diesel's master technician Gage Burlingame asks prospective buyers first. "If you do mostly city driving and don't haul heavy loads, you want a lighter vehicle that doesn't need to scoop a lot of air to run efficiently. If you're towing a lot of weight or doing mostly interstate driving, get a larger truck that can handle your needs." All of the major manufacturers offer a range of sizes, so shop for the right size to improve your fuel economy

Consider Trade-In Value
According to another of GSD's master diesel technicians, Shawn Musgrave, the most fuel-efficient diesel truck available today could be tomorrow's fuel-guzzler. "The government's fuel economy standards are tightening up, and manufacturers are responding with more efficient engines every year. The 2014 models set to go into production now will have new EcoDiesel engines that promise better economy than anything on the market today without sacrificing power."  A more efficient diesel fuel injection pump in the EcoDiesel engines lets them deliver the same power from a smaller burst of fuel. New common rail injectors also contribute to the design's efficiency. Musgrave advises keeping your truck in good shape to maximize its resale value. "Diesel maintenance is important whether you're keeping your truck for years or replacing next week, but the investment you make in maintenance today could mean thousands of dollars at trade-in time." 

Make Yours Manual
One trait that gas-powered and diesel engines have in common is that a manual transmission saves on fuel, especially in hilly territory. Burlingame says the difference from driving around a city like Boise to driving mountainous terrain in Stanley or Lowman could be as much as 8 percent. Manual transmissions typically have lower maintenance needs too; the less often your truck sees the inside of a diesel engine repair shop, the more money you save. 

Ask the Experts

"Someone who's selling you a truck will make that truck sound like the best on the lot," says Musgrave, "even if it's not quite the one you need." Instead, he suggests talking to people who are familiar with diesel trucks yet aren't in the business of selling them. "Ask a diesel mechanic, a station attendant or a diesel maintenance specialist about the most fuel-efficient options," he says. "You can learn a lot from half an hour with someone who sees dozens of makes and models." Searching online can also help, he says, but be sure your source is trustworthy. Consumer-based reports and EPA sites are a good place to find unbiased information on diesel fuel economy.