used trucks, trucks for saleHaving trucks for sale with diesel well over $4 a gallon and gas slightly below that price is a real challenge for anyone who needs to unload a fuel hog. People are turning to vehicles that get better gas mileage, and used trucks are a tough sell right now. Things that owners can do to move their vehicles faster is to obviously lower the price, but if that doesn't work, truck owners may have to pop the hood and tune it up or put in spark plugs that help performance, which in turn, increases mileage. There are several good spark plugs that you can get online that burn fuel more effectively. One is the halo plug, and I can testify to how well they work. I increased my car's performance substantially by installing them. They use a different way to spark than the ordinary ones, and after putting them in, my mileage increased about 20%. If you tweak everything you can, it will make used trucks sell faster because they get the best mileage that they can.