16 inches in scale 1/18

Hi! I want to scratchbulid Porsche Gullideckel wheels. They are 16 inches. I measured 16' to 1/18 scale, but 2,25cm diameter maybe it's too smart.
I Haven't Golf mk1 in 1/18, but i measured this 2,25cm in Audi A4 1/18 and its too smart for this model.
Please, check this diameter(2,25cm) in your Golfs mk1 1/18 and tell me if 16 inches - 2,25cm are good for this model.
I am afraid, is my 2,25cm =16" fit in 1/18 scale to Golf mk1 ?
Please help me.