I had an 2002 8.1l/Allison and loved the power and towing capabilities. It had about 85,000 miles on it and thought I would never get rid of it. Then I got a 15,000lb trailer. The gas mileage didn’t go down much but my average traveling mph did and the truck did not like hills like it used to the 10,000lb trailer.
Our new L5P Duramax is a dream pulling our trailer and I don’t miss the old truck as much as I thought I would.
Also, I don’t miss the older technology, the small gas tank and especially the engine noise level at 3200 rpm. These new trucks are so quiet.....