Hi, i think ive bent the saab rules slightly as my current wheels dont have an et number on them, but when i fitted them, i did a quick measurement of the offset and compared it to my previous aero wheels which were 49 offset, and i think the mating surface was about 14mm further from the outside edge of wheel than the aero wheels which would make them about a 35 offset

but no rubbing or bad wear problems so far, and they sit beautifully on my car.
I tell you what, i willl double chek the measurement on sunday.
But i should also add that im running on 215 45 17 tyres, and these give the following effects :-
Im only doing about 98.6 mph at a speedo reading of 100mph - no problem to me
That means that i also slightly increase my fuel consumption, but do i ? see below
I probably reduce my acceleration times by 1.5% - every little counts
These tyres also lower my car by 9 or 10mm - this may counter any fuel deficit by improving aerodynamics slightly and maybe help roadholding very slight.
With regard to kermits point of the minimum 40 offset, i think i realise why mine are not being arched, the 215s are 10mm less wide than the 225s, which is 5mm on each side. This 5mm on the outside essentially equates my 35 offset with 215 tyre to a 40 offset with 225 tyre.
Hope you like these declarations and they are open for critiques