I have a 2020 Silverado LT woth the 3.0 L Duramax and 10 spd trans. We completed an 8K trip cross country over 7 weeks and had no issues. I averaged 14.5 MPG overall which I thought was great. I have 38K miles on the truck and just had the trans serviced because GM recommends if you tow a lot or severe use it should be serviced at 37,500.