Hi - I am contemplating buying a new 2021 Suburban with the 3.0 diesel. I tow a 7300 lb Airstream travel trailer. I currently have a 2018 Suburban Premier with the 5.3L gas, 6-speed trans. The 2018 is fine towing on flat roads but struggles on even the slightest hills. Does anyone have towing experience with the new 2021 Suburban diesel? Thank you.