Basically what I'm asking about is, would getting new wheels with a wider width, and lower offsets change the geometry of the suspension? I just got an alignment on my stock 19s (lowered on eibachs) and plan on getting new 19s with lower offset and a little wider in width for both front and rears.

I've read a lot here and there that they do and they don't and they do, so I thought I could get some advice from you guys so I can choose whether or not to get another alignment once I mount my new rims.

 

Won't change your main alignment settings~your camber, caster, toe, won't be affected. You will be changing your scrub radius if your wheel center point shifts inward or outward and this can result in more or less steering feedback/response. This is due to the shifting of the Steering Axis Inclination (aka SAI).

 

Imagine a line drawn through the upper and lower ball joints to the ground. The distance between the center of the tire contact patch and the imaginary line is the scrub radius. The contact patch center is usually outboard of the SAI line/ground intersection. Wider wheels tend to increase this distance a small amount which acts as additional power steering. It seems this is more of an issue with front-wheel drive cars than RWD.

 

Even with oem wheels my alignment was off

 

Don't blame the wheel for that.

 

It's just cheap insurance to align it my shop charges 99 bucks for lifetime alignment.

 

I'm never happy with cheapo chain alignments.

I paid twice as much for a shop that specializes in Porsche to align my car. There was a GT3 up before my lowly G37S. The guy spent probably an hour sorting everything out, aligning the wheel, getting the settings even side-to-side and even paint indexing everything so I could tell at a glance it anything changed.

 

^^ This.

 

Mine is at track performance shop texas track works all they do is work mostly on bmw Porsche for daily and track driving