SonyHome

Thank you so much magne. I really appreciate you knowledgeable info. I talked to the vendor of the 38/40 offset and they claim that they've test fitted on the 2IS with no issues but have not done that with 3IS. So if you are sure 2IS fitting represents the 3IS than it sounds like both of these may be ok based on your info. I'll check to see if any 2IS owners have this wheels.

Thank you once again!

SonyHome

So I found this thread on 2IS and it does seem to fit nicely on the 2IS. As long as 3IS is same this should work.

https://www.clublexus.com/forums/is-...-wheels-7.html

So I'm think these wheel/tire setup for my winter and summer on my IS350 F Sport RWD.

Winter using stock F Sport Wheels
225/40/18 & 245/40/18

Summer 19" LFA Staggered Hyper Black Wheels with 38mm/40mm offsets
245/35/19 & 275/30/19

http://www.tirerack.com/tires/tires....omCompare1=yes

Do you see any issues with either of these setup?

magne

The 3IS have better clearance to the fenders than the 2IS, so anything that fits a 2 IS without modifications, will also fit the 3IS.
I don't see any problems with your setup, other than that the rear tyres will be a bit bigger than stock. I don't know how US laws and regualtions about this is. Where I live, they would be just inside the regulations.
You speedometer might be a little bit of, but not much. 255\35 and 245\40 is a difference of 2,8%, so you speedometer might show 60mph and you're doing about 62 if it is 100% correct with the normal tires.

SonyHome

When you say "better clearance" is that for height or width or both? I noticed the 9.5 sticks out a bit more than the stock rear and new front size using your rim calculator you provided.

magne

Better clearance references to the width. The 2IS has a lip on the inside of the fender, the 3IS does not have this lip.

Yest, the rims will stick out a bit more, but there is plenty of room, so I can't imagine it will scrape on fenders or anything, unless you lower the car A LOT.
However, where there is less clearence, on the inside, there is not much space between the shock absorber\spring and the wheel, but i believe it is enough with the setup you have choosen. Especially since it fits the 2IS.

Since you move the center of the wheel slightly, you will also alter the steering geometry slightly and a wheel alignment might be a good idea. But since it is not many millimeters difference, it is not something you have to do.

SonyHome

I've decided to go with stock F Sport wheels for winter but I need some feedback on tire sizes I would like to go with. Originally I was thinking of going with 225/40/18 & 245/40/18 but now I would like to go with 235 width on the fronts but currently Michelin X-Ice Xi3 doesn't come in 235/40/18 currently (will be released July 2014) but does have 235/45/18. Would there be any issues with below setup?

Front: 235/45/18
Rear: 245/40/18
http://www.tirerack.com/tires/tires....omCompare1=yes

I think this would raise the front a bit higher than stock but would this cause any issues?

Or would it be better to have same profile height as below?
Front: 235/45/18
Rear: 245/45/18
http://www.tirerack.com/tires/tires....omCompare1=yes

magne

Why don't you buy 4 stock 18x8" wheels and go with 225\40-18 allround?
This is a better solution than messing around with other tyre sizes that will have impact on speedometer reading and other things.
If you are going for 45 profile tires, I would buy 17" rims. There are a lot of 17" rims out there that would look good on the car.

jnjmatts

I looked all over for a 17" rim to mount winter tires on my 3is350 fsport. The problem with 17" rims is they won't clear the front brakes. I just mounted studded Nokian tires on the factory fsport rims. Works great.

jnjmatts

Sorry but if should specify that it was the after market 17" rims that wouldn't fit. Lexus 17" rims would fit but is didn't want to spend $600 per rim for winter rims.

magne

I had no problem with 17" rims not clearing the front calipers. It is just about having the correct offset.

SonyHome

But it looks like 225/40/18s actually too narrow for 18x8" wheels. That is why I'm trying to go with 235 width and Michelin X-Ice Xi3 don't have 235/40/18 until July 2014.

jaznraz

iTrader: (1)

The specs for the 225/40/18 X-Ice Xi3 on Tire Rack says they are for an 8" rim with a range of 7.5 to 9.

I'm shopping for the same thing...winter tires for staggered 18's. I'm hoping this size will work on all 4 corners. ????

magne

225 on 8" wide rims fits perfect.
ask any tyre dealer.. All the 225 tyres I've had have been mounted on 8" wide rims. They fit perfect.
The stock front wheels are 8" wide and have 225 tire width. Do you think they would have gone with that stock from the factory if it didn't fit?

I have had 4 pairs of 8" wide rims with 225 wide tyres. Both 17" and 18" rims.
Also own a pair of 17x7,5" wide rims and have 215 wide tires on these. They also fit perfect.

Whoever has told you that 225 is to narrow for 8" wide rims are wrong.
If you have they stock front wheels on your car, there is no problem to see this for yourself. The tire actually has a small lip that sticks outside of the rim.

SonyHome

Thanks for the confirmation. Perhaps I will stick with 225/40/18 & 245/40/18.

I won't say who stated its was too narrow but I was also able to see it visually on the site you give me earlier. If you put 225/40/18 with 8" wheels at 45mm offset you'll see tires are bit narrower than the wheel.

http://www.willtheyfit.com/

Also why do you say go with 17" if I go with 45 profile tires? What would be the issue if I use 18" with 45 profile tires?

magne

If you use 45 profile with 18" wheels the diameter of the wheel will be bigger than stock. So the speedometer will show wrong speed, the odometer will be a bit off, and you may also be breaking the regulations about wheels in your state\country.

The site you use to calculate rim offset does not show a very good indication of how the tire fits.
It does however give a good idea of what altering offsett will do to your car when it comes to if things will fit or not.
The best you can do is to use this site and ruler to meassure if things fit to your car.

To explain a bit to you about tire sizes, if you are not aware of this:
225\40-18. This means that the tire is 225 millimeteres wide. 40 is the sidewall hight in percent of the width of the tire. 18 is the rim size.
If you alter the profile from 40 to 45 you'll get a bigger impact on how high the sidewall will be if the tire is wider. Going from 40 to 45 will make the sidewall 5% of 225millimeters higher. (about 12mm higher)

when it comes to winter tires, there are not many sizes in low profile. Therefor a widely used size is 225\40-18. Also 225\45-17 is a very common size.

From what you have explained about your needs and wants in the previous posts, you'll be fine with 18" rims and 225\40-18 allround the car. That way you can buy 4 stock 18x8" rims, they will fit fine, have correct offsett and tire size.
245\40-18 will fit the 18x8,5" rim. But I don't see the point in splashing out the extra cash for wider tyres in the winter. These tyres are narrower than stock tyres, but will still fit your rims. However youl'll lack some of the sidewall protection for your rim. Also 245\40 differs quite a bit from 255\35. So again you'll might throw off the speedometer and odometer.

If I were you I'd just go for 18x8" with 225\40-18 allround. This gives you a lot better choises of tyres and you can do it on stock rims.

I did go for 17x8" with 225\45-17 on my car. Just because we get a lot of snow and the road gets very bumpy were I live. 17" was a good fit on my car, and the 18" stock wheels are very expensive where I live, so this probably saved me about 5000$ compared to the stock 18"

I've linked you this calculator before, it is a very good one. But in a foreign language: www.motormann.no
It shows every vital messurement in both rims and tires, and it lets you compare your combo to the stock combo.
Try to use it, even if it is a foregin language, most of the info are pictures and numbers. And those are understandable i any language