2013 GMC Sierra 2500
I am looking at replacing my current TV with a new 2013 GMC Sierra 2500 4x4 with the 6.0 L gas engine. I have found two left overs that are nearly identical at different dealers. Both have the Denal...
Forum Discussion
1oldtruck wrote:
Has anyone upgraded from the old four speed automatic transmission to the new six speed and noticed a difference. The 6.0L is the same engine I currently have although the newer one has a few extra HP.
We had a 2004 3/4 ton Suburban with the 6L/3.73/4 speed combination. With the trailer in my signature, I had to tow in 3rd as the truck wouldn't maintain speed in 4th (OD) even on flat roads.
We now tow the same trailer with a 2011 1 ton Express that has the 6L/3.42/6 speed combination. I am very impressed and satisfied with this combination. With the performance of the old truck, I anticipated needing to tow in 4th gear based on the previous performance. Our first trip out on a two lane road at 55MPH I was towing in 5th gear and maintaining speed. I am even able to accelerate in 5th gear. On occasion, on the flattest of flat roads, it will even tow in 6th gear.
