Quote:
Originally Posted by CHKelley
redfisherman007-- Thanks for pointing that out. I'm running 3.42's and actually wondering what that will do to my power and mileage once I add 305/70/17 tires.
I know my mileage might go down, hoping I don't see any power loss.
|
Hey CH,
Being as you have my exact same truck it seems and I am running 325/70R17 tires I think I can shed a bit of light on your scenario.
With your speedometer corrected (that's what my Bully Dog is for, 70mph on the speedometer is 70mph on my Magellan GPS) you will be at 1500 RPMs at 60mph. At 70mph, you will sit around 1750 RPMs. I usually cruise around 62mph on the freeway and can get over 16.5mpg with the Bully Dog set to stock. I haven't yet completed a tank of fuel with the Bully Dog on Tow but, based on how many miles I have on this tank and where my fuel guage is at I would have to say I am sitting around 16.5mpg with a mixed city/highway. I should be taking a 275-mile or so highway trip this weekend to pick up an Edible Arrangement for my mother for mother's day so we will see how she goes with the Tow tune on strictly freeway. I am predicting upwards of 17.5-18 on the highway.
As far as power is concerned, you have no worries. I pulled 12K in my trailer and the bed of my truck with the 325/70R17 tires on it 1400 miles from Kentucky to wayyyy south Texas and I could barely even tell the trailer was back there. She never skipped a beat.
I don't care what anyone else says about the 3.42 gears; i LOVE them. I rarely ever tow more than 10K though, so I suppose if I were maxxing out the GCVWR all the time I would opt for a numerically higher gear ratio. Of course if that were the case I damn sure wouldn't be running 35" tires, either! Hope this helps.
__________________
'08 QC SB 4WD 6.7L/G56/3.42, HBS Level Lift, Thuren Track Bar, SSSSS, 325/70R17 Nitto's, Weatherguard Boxes, Wheel Well Liners, Tailgate Spoiler, Weathertech Vent Visors and Floor Liners, Line-X, Tekonsha P3, Power Pup, Juice w/Attitude, Shaved BlueTec Badge 
Last edited by BroncoHound : 05-08-2008 at 11:21 PM.