2020 GMC/Chevrolet Diesel Engine
“The optional engine remains the largely carryover 6.6-liter Duramax V-8 turbo-diesel—445 horses and 910 lb-ft—but is now mated to a 10-speed version of the excellent Allison automatic gearbox, up fro...
Forum Discussion
The Allison name carries a lot of water. The name has a reputation for durability and has been used in connection with the Duramax name since 2001. They stopped putting it on a badge on the actual pickup in 2015. Clearly they still want to use the name in advertisements. How much of that tranny is actually "Allison" I have no idea. I am sure there is someone in the factory that is building the 10 speed that may have some insight.
