Hi All

I've got a 2009 S3 GS450h and I'm having a nightmare with trying to source a set of winter wheels for it.

Standard fitment is 18x8j ET45 with 245/40/18 but I generally go a bit skinnier for winter rims and had two sets of 18x7j 114.3x5 with ET40 and ET35.
I've tried 18x7j ET40 (OEM KIA) which fitted but needed 8mm spacers to stop the spokes rubbing on the calipers.
I've tried 18x7j ET35 from a 2007 RX350 which, as far as I can work, should have fitted better than the OEM Kia due to the lower offset but these didn't even fit with 10mm spacers as the spokes were hitting the calipers.

It's possible you're laughing reading this thinking 'What an idiot this guy is', that's OK... so help me out. Where am I going wrong?

Q1) Why do ET35 need a bigger spacer than ET40 - shouldn't it be the opposite?
Q2) What offset do I need to look for to guarantee fitment?

 

Offset alone doesn't account for calliper clearance. You need to look at the x-factor/back spacing of the wheel.

 

Thanks.
How do I work that out so I buy a set of wheels that will actually fit?

 

it is not so much the offsets, but rather disc size of the wheel. Hi disc, med disc, and low disc. the 450h has larger calipers in the front which require hi disc to clear or the need for spacers.

https://www.more-japan.com/blogs/201...he-disk-types/ <--- that should clarify

 

I couldn't explain it better than others before me so I'll link you https://blog.racetechnologies.com/20...rake-clearance

Or check Google. Heaps of info on how to measure your car and the wheels.

https://www.google.com/search?q=how+...rake+clearance

 

are the gs450h discs bigger then the GS350 AWD?

I'm rocking my old TL wheels on my GS.



I'm rocking 225/50R17 X-ICE XI3

 

looks like you need a 18x7 +30 offset.. also do realize the width of the wheel will helps determine offset.. 6mm for every half or quarter inch i cant remember atm