Dan Krueger writes:

How could they double
the mileage based on a hitch when additional wear and tear can't be
measured?

How could they? By putting it in the lease contract. You install a hitch,
you pay extra by some formula.

Short-term car rentals prohibit towing altogether. You pay infinity extra.

Long-term leases would not surprise me if they did the same, or charged a
penalty rate. It certainly would be exploited if they didn't. Heavy
towing is *very* expensive because it shortens the life of the transmission
before a rebuild is needed. The towing package just makes it possible to
do so.

But the same could be said of living in a mountainous region versus South
Florida.