Wheel size question.

[p3eps]

Thanks for the links...

So the fist guide says generally a 5mm - 7mm difference should be ok.
If I'm going from 50 to 45 - does that mean that the wheels will be 5mm further in the arches?
And an ET60 would make the wheels 'stick out' and extra 10mm?

[am1w]

Thanks for the links...
So the fist guide says generally a 5mm - 7mm difference should be ok.
If I'm going from 50 to 45 - does that mean that the wheels will be 5mm further in the arches?
And an ET60 would make the wheels 'stick out' and extra 10mm?

'If you reduce the amount of positive ET on the wheel then the vehicles track is widened and vice versa if the ET number is reduced. Straying too far from the original offset can be detremental as fouling to the suspension and bodywork can occur as well as eccess strain on wheel bolts or studs'.

[JonnyG]

If I'm going from 50 to 45 - does that mean that the wheels will be 5mm further in the arches?

No they would stick out 5mm more

[p3eps]

Hmmm... it seems near impossible to find a set of aftermarket reasonably priced wheels that have the correct offset.
45 seems to be the most common one available.

[Snoopy]

Thanks for the links...

So the fist guide says generally a 5mm - 7mm difference should be ok.
If I'm going from 50 to 45 - does that mean that the wheels will be 5mm further in the arches?
And an ET60 would make the wheels 'stick out' and extra 10mm?

p3eps i posted a site link for you back on the 28th Nov on your R forum when you were asking about alloys. It is a very useful website to work out if it sticks out more or in more and other things.

P3eps have a play with
http://www.venommotorsports.com/library/tirewheelcalculator.asp

[p3eps]

P3eps have a play with
http://www.venommotorsports.com/library/tirewheelcalculator.asp

Am I looking at the wheel inboard and wheel outboard increase for that?  Its -0.196, and the tyre width difference is -0.39... so do these cancel each other out?

[p3eps]

Found a set of Skoda wheels with a 51 offset with everything else correct.
They're 7.5j though - which I guess is better for winter tyres anyway?

What tyre size would go on a 18 x 7.5 wheel?  Still a 225 x 40 x 18?

If the ET45 fit and cause no problems then I'd probably rather have them.

[Snoopy]

Tire & Wheel inboard and outboard tell you how much inward and outward difference there is to your reference wheel/tyre combo.

[Snoopy]

Found a set of Skoda wheels with a 51 offset with everything else correct.
They're 7.5j though - which I guess is better for winter tyres anyway?

What tyre size would go on a 18 x 7.5 wheel?  Still a 225 x 40 x 18?

If the ET45 fit and cause no problems then I'd probably rather have them.

The standard 18s on the R are 7.5" x 18 ET50 with 225x40x18 so more or less same as the skodas.

[am1w]

Snoops:
The 8" rim will stretch the tyre slightly in comparison to a 7.5" one.
Can one keep the tyre pressure the same as with a 7.5" rim?