I have a '24 IS350 F-Sport ~17K miles that is in need of some new front tires due to the inner tread being worn. (Yes, I know about the LCA bushings) I have the 19" black chrome wheels, staggered. The stock front size is 235/40/19 and to me, they look a little stretched on the wheel. Anybody here go up to a 245/40 or 255/35? From what I read, the wheels are 19"x8.5" in front and 19"x9.5" in the rear. So, a 255/35 in front should fit properly. Not sure if there would be any clearance issues.

(I might consider doing the LCA brackets at a later date, but for now I just need to get the tires replaced.)

 

This is an old document, but might still apply...

It's called Wheel Fitment, but if you scroll down to the IS section you'll see the tire sizes as well.

Here is the thread it came from:

https://www.clublexus.com/forums/sc4...m_content=post

 

That's a pretty good guide. The IS referenced in there is a 2001 model. Not sure what the difference in steering components and dimensions vs the 2024 model are, but the largest front size recommended in there is 235/35/19, OEM is 235/40/19.

 

Yeah, I knew it was old, but the OP last updated his Post #1 in 2022.

There's lots of responses as well -- the thread is 6 pgs long -- that could possibly have answers to the same question(s) you're asking.

I didn't go through the whole thread but there seems to be a lot of helpful info with members questioning and saying what size(s) worked for them.

Good luck and please update this post for the next person looking for answers...

 

My guess would be that 245/40R19 would be OK, but you'd probably want to also up-size the rears just to keep the tire circumference similar between front and rear. On prior year ISes, going up one size is pretty common and should be fine on the 2021-2025.

 

Decided to add the photo. If you look at the side wall, it tilts inward slightly. I'm pretty sure a 245/40 would work without issue. A 255/35 I could only guess it would work. Kinda curious if anyone here has done a 255/35 in the front. If there were any rubbing issues or anything like that. I'm not replacing the rear tires, they have plenty of tread. I'm still figuring out if I want to replace the LCA bushings now or do it at a later time. Logic would dictate I should change them first, then replace the tires. Trying to be mindful of the budget.

 

If you suffer from inner tire wear, you might want to do the bushings first, otherwise you’ll be wearing out your new tires.

 

I agree with KJ. You should upgrade your LCA bushings before or at the same time to prevent additional tire wear. After I changed my LCA bushings, I went up in size on my tires. This made my speedometer off by .9 miles per hour. So, at 70, I'm doing 70.9 MPH.
1. My tires are now Pirelli PZero AS Plus 3's. 245/40r19 fronts and 275/35r19 in the back.
2. Lowered on Eibach pro kit springs
3. 15mm spacers in front and 20mm spacers in back.
4. No rubbing.




Hope this helps.

 

I went ahead an ordered the RR Racing LCA bushings.My father's day present to me.