Hey bcguy, when I haul my 5th wheel over the Oregon coastal range there are times I never touch my breaks going down steep grades. If fact it slows down so well I need to hit the “diesel” pedal to gain speed. The higher the RPM the more the break works, so at 3000 RPM it’s holding back really well for me. Tow/haul mode will down shift automatically going down hill or do it manually to get the RPM up.

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2008 Dodge 2500HD 6.7L 4X4 Laramie
Edge insight, Amp tailgate step, 4" Boss Bars, rear air bags with compressor, spray in bed liner