ET37 will give you flush wheels with the outside. The other ET will let the wheels be more on the inside of the wheelarch.

The std 7.5x18 ET51 Zeniths are already a little bit "skinny".They dont really fill out the arches.

Driving 8x18 ET44 on my RS now, these fill out the wheelarches. Have tried 8x18 ET35, but they stand out too much.

And 7.5 ET37 is comparable to the 8.0 ET44 I am driving. You will only have a bit more room between wheel and inside of the wheelarch.

I thought the 18" Zeniths sat a little too much inside the arches too. Flush is what I was going for. So its the 37ET for me :-)

OK Guys I am ordering my new BBS wheels today and I have a choice of offset on them which is either 37ET or 48ET on a 18"X 7.5 rim I checked the offset calculator and the 37ET is sticking out 23mm more then the 17"Zenith and the 48 is 12mm. Will the 23mm stick out too much? or will I just go for the ET48?

Thanks guys

To help you put everything in perspective here are some pics to show the offset etc.

This shows 7.5J ET45 rims. 7.5J ET48 rims will sit 3mm inboard of these or 7.5J ET37will sit 8mm outboard.

this shows 8J ET45 rims 7.5J ET48 will sit 9.25 inboard of these or 7.5J ET37 will sit 1.75mm outboard of these.

PS> There is 6.25mm difference between the two photos above with the 7.5J sitting 6.25mm inboard of the 8J (as they are both ET45).

I hope that helps. Decisions, decisions? but I think you could safely stretch 1.75mm and get the ET37s.

One final point though, just to 'throw a spanner in the works'. If I was looking to change my wheels to 18s I'd be going for 8J not 7.5J rims. This will spread the tyre slightly and sharpen the handling (in the dry).

Edited 31 March, 200917 yr by bahnstormer vrs

Useful, practical post above

I'd go 8x18 as well

Steve

OK Decided Going for the ET 48 :-)