Review on 🚀 K&N Cold Air Intake Kit: High Performance, Increase Horsepower: 50-State Legal: Compatible with 2004-2005 CHEVROLET/GMC (Silverado 2500 HD, Silverado 3500, Sierra 2500 HD, Sierra 3500) - Model: 57-3047 by Cody Bowie

Adapted to above 2004 GMC 2500 4-Door Long Platform 4x4. I use the hypertech programmer as my only productivity boost; It has 3 settings, 90 hp is the highest. Before we installed it, the programmer had a big impact on fuel economy and performance. I never felt it was working to its maximum until I installed K&N. Before installing the filter, we were driving about 18 mpg on the Missouri-Georgia freeway. Stepping on it produces black smoke and the truck runs great. After installing the filter, we step on it and black smoke appears at first, but very little. The fuel-air mixture is almost perfect and the truck burns almost all of it. I have a feeling it works best with the programmer and filter installed. We're getting 19.2 mpg now and with a 24-foot-long pointed gooseneck front trailer and 8 feet between the box/closed trailer's inner fenders. Just to give you an indication of size. The truck runs 14-15 mpg with a 10,000 lb load. The trailer has two 7000 lb axles. The run is based on a trip from Missouri to Georgia.