[darkvader0]

So I goofed on my order and followed the sales rep's advice to get all-season run-flats and now I have dinky 8" wide rims with 225 tires all around.

Now I am rather inexperienced at wheel fitment, but looking for a solution I like. I keep coming to this:
F: 18x8.5 w/ 245/40-18
R: 18x9.5 or 10 w/ 285/35-18

I'm worried about the 285s on the rear. Is that too wide to fit at all? I'll be stock height and don't want to worry about any rubbing of any kind.

Thanks to anyone with any knowledge on this.

[Coconut]

I think you mean your wheels are 19" assuming you got the ZTK package based on the 8.5 and 9.5 wheel widths.

Factory ZTK tires are 245/35-19 front and 255/35-19 rear.

You could also do 245/40-19 front with 275/35-19 which will keep the front to rear tire dia. difference <1% for XDrive.

[darkvader0]

No, I wish. What's coming with my car are 19x8 all around with 225/40-19.

I actually want to step down to the 18s. I'm weird I know lol.

[WilcoJunoHotel]

Has anyone fitted 285/35-19 (or wider) rears on their OEM ZTK rims?

Considering this on my RWD car when the 255/35-19 OEM tires wear out. Should eliminate most of the speedo error too.

The rim width (9.5") should be fine, just concerned about rubbing in the wheel wells and so forth. Not going to dick around with the ride height or anything - that will be staying stock.

[Wasp_Factory]

I thought that 275 was the max recommended width on a 9.5 rim? 285 is going to be super baggy, but I'm sure others have gone to 275 with no problem. There is a lot more room between rim and strut at the rear than at the front.

[darkvader0]

This is a 275/35R18 on an 18x9.0 ET37 rim. The tire sidewall is perfectly flush with the rear fender with this setup. Was exactly what I was looking for.

The rim on the ZTK will poke out a little more, but you have those (roughly I think) 4mm flares, so that should help decide.

[hooked]

285 might be a little too wide for a 9.5" wheel.

I think 255 for a 8.5" and 275 for a 9.5" are the max suggested widths.

I have the ZTK package and looking at this for my next summer setup:

245/40R19 = 26.7" x 9.6"
275/35R19 = 26.6" x 10.8"

Came with Michelin PS4S:
245/35R19 = 25.8" x 9.6"
255/35R19 = 26.0" x 10.0"

I have xDrive so want to keep diameters within 1%. Also, when I'm really getting on it, the rear tends to step out more easily than the front so an extra .8" of width out back should help with that.

This change would lift the front ~.5" and rear .3," soften the ride a bit, but not sure about rubbing but have seen others go up 10-20mm in tire width on the ZTK (893M) wheels on the stock suspension and report all is good.

[WilcoJunoHotel]

Yes, I will talk to some tire experts before I do anything. Don't want to negatively affect the handling or safety. I have seen both 275 and 285 as max size.

Just wondering if anyone is currently running them.