I have a 04.5 duramax 3500 and I'm not sure when to use the tow/haul button on my gear shift also using this will it help my MPG? Thanks.
TV: 2004.5 Chevy Silverado CCLB 6.6L 3500 DRW, K&N, EFI Live 60hp economy/tow tune, 4" magnaflow exhaust, B&W gooseneck W/ B&W Companion
S&W M&P 40cal in the door pocket...
2012 28.5' Jayco Eagle RLS w/super slide
Ruger 45cal on the nightstand
