Dieting. Rim Weight? Which is lightest?

[Bruce2]

Originally posted by MattKab

Porsche 911 Fuchs Forged 16x6 17.0
Porsche 911 Fuchs Forged 16x7 18.0
Porsche 911 Fuchs Forged 16x8 19.0
Porsche 911 Fuchs Forged 16x9 20.0
Porsche 914 6-cylinder 5-bolt (rare) Forged Mg 15x5.5 7.0

Porsche 944 Turbo/951 Fuchs Forged 16x7 15.0
Porsche 944 Turbo/951 Fuchs Forged 16x8 16.0

These numbers are way off. There's no way a 6x16 Fuchs weighs 2lbs more than a 7x16 Fuchs from a 944.
A 7x16 911 wheel weighs the same as the 944 version, they are just shaped differently, yet this list says they are 3lbs apart!
The 5.5x15 Mahle is in the 9.5-10 lb range
It looks to me that the guy who created the list simply guessed at the weights:
16x6 17.0
16x7 18.0
16x8 19.0
16x9 20.0

Gee, the width increases by 1", so the weight must increase by 1lb. Where do they get that?