For a top-notch big rig that runs like a dream, it's important to have excellent semi truck engine parts installed that are designed for durability, efficiency, reliability, and power. At 4 State Trucks, we have a huge selection of aftermarket and custom engine parts and accessories that are all built to last. We've got what you need to ramp up the power of your 18 wheeler so it works as hard as you do. Shop great products for Peterbilt, Kenworth, Freightliner, or any other make with help from 4 State Trucks.