Front wheel width

Hi

How wide front wheels could I use before starting to affect steering/tracking on street use widebody Soarer oem suspension + coilovers ?

Might be an idea to post in the suspension forum, but...

That's a very open-ended question, as any change will affect the steering.

What have you actually done to the vehicle? Are you asking about tyre/wheel assemblies? Are you someone who thinks the "stretch"fad looks cool? What, if any, are the legal limits that may apply - some countries require certifications if more than a couple of inches more than OEM?

As a general guide, increasing the offset will increase the scrub radius and this will increase kick-back, increase steering loads when turning, usually increase bearing wear, increase any steering wandering/ascillations, etc.

As a general guide, ensuring all bushings are in good condition - preferably upgraded, wil minimise deflections from the increased loadings, and increasing the negative camber a LITTLE will move the mean tyre loadings inward, reducing the effective scrub radius.

There are many, many factors, but if it's purely for "looks", are you more concerned with the total wheel/tyre assembly width, running it as close as practial to the wheel arch lip, or both? If you're not too concerned about inner arch clearance, and are prepared to limit the lock(s), the outer edge is really limited by guard clearances, the inner may need to clear the steering linkage on full lock - depends on vehicle's OEM design - and the stup spring, but the coil-overs should have helped there.

If you're lucky, your tyre shop will have a "dummy wheel", something like this - https://cctek.square.site/product/wheel-tek-2-0-master-kit/25 , there are different designs - which are adjustable for offset, width, and diameter and allow diferent tyres to be check fittled at different widths and offsets, for the best fit and/or appearance. Then you can order wheels to be built to the spec's you need for the tyres you want to run.

Uh, as you're in Ireland, you may also want to look at "all weather", or "all season" tyres, as the more popular "semi-slicks" may not only lack the water clearing on roads that have surface water, but be hard to keep at a reasonable operating temperature.