| No, the bully dog will change the factory speedo if it is used by itself. I didnt install the outlook on mine and it reset the speedo for my bigger tires. When you program it into the truck it asks what size tires you are running so it can correct it. If you use the outlook you can set it for what tires you have but im not sure if the original speedo stays correct.
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2007 White Chevy Silverado HD LBZ, CC, SB, 4x4, suspension maxx torsion keys for 3" front lift, 20x10 Moto Metal 951C, 325/50/20 MT Baja ATZs, escalade handles, 5% tint all around, no muffler, 5" tip, escort 8500 radar detector |