2020 GM/Chevy gas 6.6L max towing test

ShinerBock wrote:
There should be a caveat with N/A gaser tow ratings such as you loose X pounds of rating every Y feet above elevation instead of just saying it can tow 16,000 lbs. Unless doing 25 mph at 5,000 rpm without any power to pass is your idea of towing.

IIRC the OEMs used to derate the GCWR of vehicles with normally aspirated engines 2% per 1000 feet of elevation, which of course translates to a reduction of 22% for the top of the Ike. Reading the towing guides for both GM and Ford I can't find any reference to this.