Wheel & Tire Setup Advice

[Snehal Banik]

I own a 2012 IS250 AWD and my current stock wheels are 17x8 and my tires all around are 225/45/17. I had a pair of 3is wheels laying around and the rears are 18x8.5 & 255/35/18, and the fronts are 18x8 & 225/40/18. I was wondering if I am able to mount this set onto my car and if I am able to, would I have to add a spacer or change the tires? I am fairly new to understanding wheels, tires and what not, so any advice is appreciated!

[J Henderson]

That setup with those tyre sizes would be fine since the rolling radius of the front and rear wheels would be almost identical.

You won't need any spacers.

[Snehal Banik]

Running these sizes would be okay, even though I am AWD?

[J Henderson]

Yes, if you input the details of the 3IS wheels & tyres on 

https://www.willtheyfit.com/

You'll notice there will only be 1.5mm difference between the front and rear axles. 

[H3XME]

On 5/14/2024 at 7:52 AM, Snehal Banik said:

I own a 2012 IS250 AWD and my current stock wheels are 17x8 and my tires all around are 225/45/17. I had a pair of 3is wheels laying around and the rears are 18x8.5 & 255/35/18, and the fronts are 18x8 & 225/40/18. I was wondering if I am able to mount this set onto my car and if I am able to, would I have to add a spacer or change the tires? I am fairly new to understanding wheels, tires and what not, so any advice is appreciated!

You can use them as they are. They will fit without spacers or any modifications, but as a rule of thumb, it's better to have a squared setup on an AWD car. However, people put staggered wheels on them, you shouldn't have any issues, but in the future it would be good put 235s on the rear once the 255s wear out. 255s will also have a negative impact on fuel economy.

[Linas.P]

I think Lexus does recommend square set-up for AWD, but I have not heard of any issues (anything being damaged on IS250 AWD), note that this is UK forum, so there is very little knowledge about AWD cars as we simply didn't get that option in UK. I happened to own US imported AWD for short while many years ago, mine had square set-up, but also only know quite little about them from US forums at the time.

So it could be summarised - in conclusion the wheels will fit fine, it is not recommended to have staggered set-up for AWD, but it doesn't seem like AWD system in IS is fragile or very picky (like Subaru for example, would just explode if you put wrong wheels on it).