Stock wheels:

IS350 18" RWD :
Front: 225/40/18, 18x8, +45mm
Rear: 255/40/18, 18x8.5, +50mm

So, you are going to have a 19 x 8.5 front with the same offset as a stock 8.0 wheel. Okay, the 8.5 will stick out 1/4 of an inch more. Boring in my opinion, but whatever you wish. A +38 to +30 looks better.

The rear you are saying you are going to extend 30mm out towards the fender, vs. the stock wheel. That is what is going to happen when you install a +20 19 x 8.5.

The stock wheel is +50.


So the rear wheel will be 1-1/8" more sticking out, compared to a stock wheel.

I'm pretty sure it will fit. The rear will be very flush to the fender. You will need to run a 245/35 rear tire. If you even plan on lowering it, go 235/35 to 245/30.

The only problem is, the car is going to look like crap with a major flush wheel in the rear (and only an 8.5" one after all ) and a really sunken wheel in the front.

If thats what you want, go for it. The wheel you like is just a copy of so many other wheels out there (a flower shaped mesh) that why not buy the correct offsets and be done with it?

Your only other option is running the +45 front and use a 15mm hubcentric wheel spacer to even it out to match the rear. That would give you a +30 front, but I still think you are going to have the back sticking out looking like Joe Dirt's Daytona.



My $.02

 

thanks again Lama...i am not really worried about the front yet, spacers/adapters are easy to get in CA especially when there Fred 20 mins away... anyway the Rear will really Stick out of the fender??? Woww....I would thought it lines up with the fender, maybe like a typical 19X9.5 38 to 40 offset...

 

what lama said is what i was afraid you'd run inot. a decent fitting rear wheel with a crappy fitting front.
are you sure you have to have these wheels? they're nice looking and all, but it doesn't seem worth it to get a good fit all the way around when you could buy something else that will fit right all the way.

the rear won't stick OUT of the fender, it will be flush, which is what you want.

 

i'll just use spacers for the front...so problem solved!! thanks guys!

 

ok i already did a search and i just wanna confirm my findings cause i still dont understand too much about offsets and you guys are the expert. so here it is. if i have a set of mrr gt1's 19x8.5 front and 19x9.5 rear with 45mm offset and if i get 235/35/19 tires in front and 275/30/19 will there be any rubbing issuses or any other issues? or fender mods or anything like that? thank you in advance.

 

forgot to mention i have no drop and i am on the sport suspension. thanks.

 

might be better if you ask in the tires/wheels section also.

 

Pretty conservative offsets there... *sorry cant help with your question thou*

 

not 100% sure but you shouldn't have any issues. i was talking to my homie, eric, who runs supreme power parts today and he said there was a guy there with that same tire setup today and there were no issues.

 

i doubt u will rub if u dont plan on dropping it anymore. and id go with a 30 series tire up front

 

i plan to drop later on eventually whenever i can afford springs or coilovers

 

since 45mm is conservative offset, does that mean it will not be flush or what not

 

i would like an aggressive look but dunno much about offsets so any help would be appreciated

 

my guess is that +45 at fronts will look full faced, you might also need spacers with that offset.

i have 8.5 19's +40 at the front with 235/35/19 CSCII and it's flush enough for me (not hella flush though lol) and i kept a reasonable safety margin between it & the fender. I wasn't after a loud aggressive look anyways


& you most defiantly want to drop the car a bit, best of luck!

 

with that set up, its pretty conservative and should have no problems. if you plan on dropping the car any lower, you might wanna run a 225/35 front. a 275/35 rear should be find but if you like, a 265/35 would be on the safe side.