Hi

Can anyone explain (in simple terms please lol ) what difference the offset makes.

E.G. The wheels have an offset of 52.5 (i think), What would be the result of putting wheels with a larger or smaller offset - to the standard ones - onto the car??

Are there any benefits or drawbacks from a bigger/ smaller offset?

Appologies if this is a stupid question

Thanks

well the main is it might not handle as good as it should and if you got to big tyres can rub against archs

Not a stupid question at all...

Offset is the distance between the flange of the wheel (the part which rests against the hub when you fit mount the wheel ont he car) and the centerline of the wheel.



A wheel with 0 offset had the mounting flasque exactly at half width. Offset values are typically expressed in millimeteres and printed on the rim. The value is usually preceeded by the letter E or ET. i.e. ET25 would be an offset of 25 mm between the mounting flange and the wheel centerline. The smaller the offset value, the outer your wheels will stick, increasing track width.

Note that the standard offset is very precisely calculated on your car. The offset value is determied by the entire front suspension setup. Fitting wheels with different offset is likely to change the steering reactions to varying degrees. Standard offset is calculated so that if you draw a line (imaginary) which goes from the Mc Pherson strut top mount, to the lower link pivot point, and hence extend it to road level, it should fall exactly in the middle of the tire. This will ensure no adverse steering reactions when you drive over bumps during accelleration or braking. Not all adverse reactions can be eliminated however, especially with very low profile tyres, but this is the principle anyway.

Blimey, well done Nick!!

And of course, putting wheels on your car with the wrong offset can bugger your wheel bearings up very very quickly and scrub your tyres out quick to.

Nice explanation there Nick.

Yep, the ST wheels are 52.5 offset.

I wonder how far one could co without excessive bump steer, bearing wear, rubbing etc. 5mm each way would seem unlikely to cause serious problems.

There's also the fact that some tyres have wider treads than others, despite having the same nominal size, so altering the offset with one type of tyre might be ok, but with another might cause rubbing on wheelarch or inner liners.