RE: [A/S] Yet Another Tow Vehicle Question - Chevy Duramax

["Perry Joe Scudder" <perryjoe@xxxxxxxxxxxxx>]

Hi MaryAnn,
You will get lots of positive feedback on this vehicle and its twin the GMC
Sierra as tow vehicles. I have had the GMC Sierra, like Patti's, for a year
now, and have been very pleased. I pulled my 34' Limited Front Kitchen all
out through the Rockies last fall and found it to be a wonderful tow
vehicle. I get about 20 MPG solo, and 13.5 MPG towing the trailer. I have
15,000 miles on my truck now, and the Fuel mileage keeps creeping up slowly
the more miles I put on (I started off at 17 MPG and 11.5 MPG on the first
couple of tanks of fuel). I don't know how much longer this improvement will
keep up, and I don't expect it to get much better. You mentioned the two
different rear end ratios to consider. I don't know about the Chevy version
of the truck, but the 2004 GMC version did not offer - or need - the 4:10
gears for towing any Airstream on the market today. I tow at 65 MPH in Cruse
on the Interstate system, and seldom shift out of O/D except in the
mountains, and all I do there is shift into 4th gear about 95 % of the time
and 3rd gear about 5% of the time. I was told the lower gears would have a
tendency to over rev the diesel engine, so they were not offered. I know the
engine will go into the red line zone on a down shift going down the
mountain when in the Tow/Haul mode and you apply the brake to slow down. I
read a Tech Note in Trailer Life the other day where some one had ask if
this was safe for the engine. The Trailer Life Tech Group quoted a tech
bulletin from GM that stated the engine was not allowed to exceed the REAL
danger RPM range in this case, before the Allison Tranny would let it shift
back up. This feature of using the engine to hold back the rig when going
down hill is really nice with the diesel.

Joe Scudder
WBCCI 8624