Lifting and lowering aren't just for the gym. Whether to lift or lower is also an important question for diesel truck owners who wonder if changing their truck's stance makes sense. They certainly change the style of a truck, turning a Ford with a Powerstroke engine into a lean, low city-slick truck or giving a Dodge-Cummins diesel rugged off-road good looks, but do they change how a truck functions? Boise, Idaho area diesel maintenance specialist and master diesel mechanic Gage Burlingame with Gem State Diesel has a few pointers for anyone who's looking to modify a truck with lifting or lowering kits.

"Any lift kit changes your truck's suspension, and that's going to change how it handles," says Burlingame. "A different suspension system means a different center of gravity, which can affect how your trailer handles when hauling. To minimize this effect, don't go too high or too low - your truck was designed for a certain height, and going too high can make it top-heavy. That's not something you want if you're traveling on twisting mountain roads." Raising and lowering your truck won't do much to change its towing capacity, says Burlingame. "If style's a consideration for you, go ahead and boost that GMC/Chevy Duramax model. Just don't go too high if you don't want to fight your truck for control on sharp turns."

"A lift kit isn't just an investment when you first have your diesel engine repair center install it. It's also going to cost you some fuel economy. Larger tires are going to cost you some of your power unless you swap out the gears to go with them. Because factory-standard trucks are optimized for minimal drag at their showroom height, they can lose some of that efficiency when boosted on big tires. The good news is that these costs are usually small. Many owners might not even notice a change at the pump." Lowering a truck, he says, usually makes little to no negative impact on efficiency and may even enhance it. "Think of how jockeys bend forward on their horses, and you get an idea of how a lower center of gravity and reduced drag can improve your truck's fuel efficiency."

For many drivers, one of the best things about lift kits is the way they change the ride. "Drivers who like lift kits like having that high vantage point. They want to feel the road, and bigger tires deliver that. You know you're in a truck, not a little compact car, when you're lifted." The key, says Burlingame, is finding a balance between performance and style. "How hard does your truck work? If you need to maximize efficiency, towing power and control in a work vehicle, you probably want to invest in a leveling kit or stay pretty low when lifting. If your truck is purely for pleasure, make it even more exciting to drive with a kit."