Avant towing capacity discrepancy

[Livolsi, Stephane]

Interesting....?

I just bought a boat, and it is kind of biggish so I wanted to check the
towing capacity on my 88 5ktq avant.  My owners manual sez maximum
trailer weight (with trailer brakes) is 2000 lbs, without trailer brakes
is 1455 lbs.  

The Haynes sez 2976 lbs (no distinction between brakes or not) for KH
engine I believe (I have an MC and it is not listed)  There is a
notation at the bottom that sez for North American models, check the
safety decal on the door post.  I am in north america, and I didn't find
a decal.

The more important thing is, why can European models tow more than NA
models - all other things remaining equal avant, manual, 5 cyl turbo?