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 2020 Duramax will be the 5LP which has been out since '17 and the new transmission appears to be impressive and I wouldn't have any concerns here. Having said that I would personally wait for the second model year to purchase one of these trucks or at the minimum 6 months into production if I was really in a bind.
