Wheel Offsets

[Chris 9-5]

The factory saab 17 wheel has an offset of ET49

If you put one on with an offset of ET40 for example does it sit further out, towards the wheel arch, or further in towards the inner wing?

Also what is the best size for 18" tyres?

Thanks Chris

[SahhhB]

The smaller the offset, the farther out the wheel will sit.

[Kermit]

Yep, mine are 40 offset and there is very little room between tyre and arch. The nearest you will get is using 235/40-18's..this will give a 1.72% inaccuracy of the speedo, at a speedo reading of 70mph you will be doing 71.2mph. I take it you're gonna need 18's?

[Chris 9-5]

Thanks Guys, and Kermit, not sure yet just doing some research

[Cambio]

Originally Posted by Kermit

Yep, mine are 40 offset and there is very little room between tyre and arch. The nearest you will get is using 235/40-18's..this will give a 1.72% inaccuracy of the speedo, at a speedo reading of 70mph you will be doing 71.2mph. I take it you're gonna need 18's?

Isn't there a way to correct that?

[aeropilot]

What rim width are you looking at for the 18"....7.5" or 8"..?

If 7.5" then 225/40x18 tyres will be ideal, as these give as near as an identical radius to the factory fit 17" wheels with 225/45x17 tyres.
These will also be OK on 8" rims as well (this is what I have on my Hirsch wheels at the moment) but, 8" is at the far end of the rim width range for this tyre size. So, there is very little bulge in the tyre sidewall to help protect the rim edges when parking etc., and I've quite badly damaged 3 out of the 4 Hirsch alloys, within the 4 months I've had them on....

Therefore if looking at 8" rim width I'd recommend the 235/40x18 tyres.

[Chris 9-5]

Thats handy cos the 225's are considerably more available

Thanks!

[opjose]

Originally Posted by Cambio

Isn't there a way to correct that?

Yes via the Tech II.

[Fliptop]

No 18" option on Tech2 for 9-5s, only 9-3ss...