hello there. I recently put work vsxx wheel on my 2015 is350 f sport cause I got a good deal.
Front 19x9.5+40(R)
Rear 19x9.5+39(O)
so far the tire size is 235/40/18 all around but now I have to get new tires so I was wondering if I could have different tire of size for front and rear. My car is not lowered at all. I won't be lowering for a lot time so far so please give ma good suggestion and I would be getting Michelin sport tires all season

 

Typical tire size for 19X9.5 is 265/30/19.
Not sure if that may be too big for the front. You could try 255/30/19 all around also.

 

Actually I'm so sorry my rims size is 18x9.5+40 front and 18x9.5+39 rear. So can I still run 265/30/18 rear and 235/35/18 in front

 

Despite the offset of the wheels, they are the same size is terms of height and width.
Ideally you would want to use the same size tire all around.
A 265/35/18 will look good and give you a nice ride.
It would be hard to put different size tires front and rear since the rims are the same size...matching the circumference is almost impossible.

 

So if I will put 265/30/18 all around will I have any issue you with rubbing or fender work or can I do 255/30/18 front and 265/30/18 rear

 

I would go with the 265/30/18 all around, but that's just me. If your IS is not AWD, you could chance the 255 and 265, I'm not sure if it would affect anything else like the ABS, VSC or TRAC.
The offset numbers seem odd for the pic...but I find those 3 piece wheel offsets odd in general.
Chances are there will be rubbing in the front at full lock turns.

 

My is350 is rear wheel drive. So I think I will go with 245/30/18 front and 265/30/18 rear.

 

That's a big difference in tire size...I would be concerned the ABS and VSC will not function properly...they could activate when you least expect it.

 

Yeah you are really a big help thank you. So 255/30/18 front and 265/30/18 rear. Will that work

 

I think I have to go with 225/35/18 and 265/35/18. I can't find tire with 265/30/18 ?

 

I think you meant 255/35/18 and 265/35/18.
Looks like no one makes a 265/30/18.
The good news if it does rub it will be on the inside, so you could add spacers to fix that.

 

Okay perfect then I will go with that and thank you so much for helping me out. You are the best