I was thinking of changing the wheels on my 2002 ST170, would this be a golden chance to get wheels with slightly more offset so they fill out the arches a little bit ?

If so, any idea on how I would calculate it ?

Thanks

 

The lower the offset, the further out they will sit. Your standard wheels are ET52.5, a wheel that's the same width and an offset of say 42 for example, will sit 10.5mm further out than the originals.

If you buy a wider wheel you also need to take this in to account, if your originals have a width of 8J (8"), and your new ones are 9J, add an extra half inch in to your calculation.

Don't go for a wheel of too low an offset as it will mess with the geometry of the car and will wear wheel bearings quicker. Lowest I would go to not noticeably affect handling would be 42.

 

Thanks for the information, I have some working out to do

 

ditched my OE wheels and fitted et37 7x18s and looked pukka and no need for axle spacers then either

 

That sounds great, any photos ?

 

car was sat on -30 eibach springs btw

18s



and on 7x17s with et35

 

Personally, 17" wheels & 30mm drop on Eibach springs is the perfect setup on a mk1 Focus.

Thats what I had on both of mine, running 205/40 & 215/45 tyres. The 205's were like rubber bands & was a bit too hard a ride. The 215's were just right but obviously the tyre is a bit thicker.

 

my bottom pic shows mine on the -30 eibachs with 17s and was running 215/45s and it did handle way better than the 18s for sure hence 18s being sold on

 

I was looking at going to an 18" wheel, but did wonder about it being to big. Not meaning to go too far off topic, but what is the off set for a set of MK1 RS alloys ? and is the RS wishbone wider ?

 

just remember a bigger rolling radius will make the car slower

 

I put 18s on my old ST170, suspension is already firm as standard and it did ruin the ride, wish I stayed with 17s! They handle really well as standard, if I had another one, I would probably keep the original wheels.

 

It's slow enough as it is

Thanks again for all the information, much appreciated.