I remember a few months back there was a tempest in a teapot when someone asked about using their 911 as a tow vehicle.
Here's a page out of a 1983 911SC ROW owners manual. The Porsche owners manual clearly states that the max towing capacity of the ROW 911SC is 5071 pounds and is acceptable up to a 16% grade if a Porsche towing hitch is used.
That seems like rather a lot, but Porsche said it, not me.
Regards,
Jerry Kroeger