wixis

Ahh okay. Is this normal with the factory wheel geometry, or are you running negative camber?

Warhorse

I also have a 2014 IS350 F sport RWD and I've taken it to 145 mph on a runway in sport mode and it didnt feel floaty at all. It felt quite controlled at that speed actually. My car is 100% stock, except for a duck tail style carbon fiber spoiler on the rear, but that isnt providing any down force on the front end either. High speed runs have alot to do with tires too, not just airflow.

V00D001

Front inner tire wear is common for 3IS cars with the OEM Lower Control Arm bushings. There are so many people that average less than 15K on front tires due to the dramatic toe changes during the compression of the suspension. An easy way to correct this is to use RCF Lower Control Arm (LCA) bushings or aftermarket units. You can also get an alignment and tell them you want a little toe out (this can make the car feel unstable - generally you want a little toe in or 0° minimum).

The RCF bushings may still allow a little inner tire wear - but should improve the excessive front inner tire wear without too much increased NVH.

Aftermarket versions add more NVH, but tend to stop the inner tire wear. They also reduce the wandering/floaty feeling at speed and especially hard braking. The front end feel is way better - but if you drive on terrible roads, you may not like the increased harshness they add. I have the Figs 90 durometer bushing kit. IMO, one of the most dramatic, and best modifications to the IS.

CASeoul

https://www.shopfigs.com/v3/CAT-G3-L...91K-90-IN-BRKT

^ Is what I got, if you have access to a press or know someone who does you could press these into your oem brackets.

https://www.shopfigs.com/v3/CAT-G3-L...LCA-SP3491K-90

Installation shouldn't take more than like an hours labor for install, I'd get an alignment as well after.

Edit: ooh saw that others had replied lol a bit late to the party

Warhorse

Yep, just replaced my front tires for this exact reason. It's great for handling, but the inner tire wear does suck. However, my tires did have 40k miles on them, but the outer part still had tread above the wear markers while the inner part had steel belts starting to show.........

I'm gonna have to look into that bushing kit.

Ellingtoni

I also came from a G37 (Sport Coupe in my case) and normally drive my 2016 IS350 F Sport in Sport or Sport +. I have not noticed this, at least yet, and have new Michelin Pilot Sport A/S 3+ tires all around.

Could the issue be from having mismatched treads on the front and back?

Warhorse

Nah, my tires were matching set all the way around and it still happened to me. I had Falken Aventis tires at all 4 corners. Staggered size, but same tread. 225 up front and 255 in the back. The staggered size plays no role in that though. My new tires are Pirellis. 225s up front and 275s in the back. I wanted more meat in the back so I went wider.

V00D001

Has nothing to do with the tires - the root cause is when the suspension is moving there are dramatic changes in toe....mainly toe-in is what causes the front inner tire wear.

Look at these two videos - pretty much all the info you need to understand what's happening.
Figs: RR Racing:

kj07xk

Nope. I also have Michelin Pilot Sport A/S 3+ on the car, and after putting on the FIGS, I added new front tires and an alignment. Now 2 years later I’ve got a ‘wub-wub-wub’ sound from the front, which was very noticeable when I put them back on after taking off my winters. The sound probably got progressively worse last year, but slow enough change that I didn’t notice.
The sound is not there with the winters, nor if I put my rear A/S 3+ on the front, so it’s definitely the front wheels/tires. (Had the wheels checked at a wheel repair place, all good. Had the wheel bearings checked, all good.)
So in two years of summer driving, about 10k miles total, the 80 durometer FIGS bushings don’t prevent inner tire wear (tire place where I bought them said they now have minor cupping, probably the source of the wub-wub-wub sound, very obvious in the 20-25 mph range).

V00D001

I have an AWD and about 5K miles on my 90 duro Figs. My A/S 3+ tires on a square 18x9 with a 245/35 setup are wearing very evenly across the width. I am also lowered 1.25" on RSR coilovers. If you're not getting the same inner tire wear on your winters, it's something other than the Figs. Have you checked your alignment and had the tires/wheels rebalanced?

HOMER350

One thing I don't hear much about these bushings is the improved stability while braking. While I'm not in the habit of ever having to brake real hard....if/when you do having the improved bushings has the most impact, imo. I had installed the Lexus OEM bushings for RCF. $85 shipped from Japan.

kj07xk

Agreed. Emergency braking (85 -> 40) before replacing the bushings was just plain scary, car wanted to wander all over the place, really had to fight the steering wheel.

kj07xk

There was probably no noticeable wear in the first 5k (first year after installing bushings and tires, AWD staggered). Winters (square) only get about 2k per year, so will take longer to show up.
Didn't notice the noise last year on the A/S 3+, as it probably increased slowly, but after changing over to them this spring, the sound difference was very noticeable, and similar to what I recall having a couple years ago before installing the FIGS and replacing the tires..
Just had the alignment checked, and it had barely changed from the alignment 2 years ago, and still very good.
I can get them rebalanced, but not likely the cause, as the sound is obvious at 20 mph, and it comes from both front wheels/tires (get the sound when either one (or both) is mounted), so both going out of balance is pretty unlikely, and to be that far off at a low speed, would be horrendous at highway speeds. There is no vibration, just noise.
Could be that the 80 duro bushings (logged into the FIGS site to verify what I ordered) allow just a bit too much movement, so I'm getting some inner wear. You've got 90's, and probably made a better choice.
I have a pair of the RCF bushings, so I may put them on and get some new tires, to see how they hold up (haven't yet seen any duro rating for the RCF bushings). The wub-wub-wub noise is getting annoying.

kj07xk

Just to close my comments, took the car to get Road Force balancing done on the front wheels. Could see while on the machine that the left front tire is slightly out of round and probably a contributor, even though the noise is present without that tire on the car, The right front appears round, but was slightly out of balance.
Sound still persists after balancing, but perhaps now just comes from the out of round left tire (will do more testing to see). Don’t think anyone does tire shaving of driven tires anymore, so maybe I’ll see if I can rig something up to shave them round (interesting home brew stuff on the web).
Bittom line, the 80 durometer FIGS may be allowing some inner tire wear, but probably not the cause of the noise I get from my tires.

V00D001

Good to know. Of course, not the same tire or car for that matter, but my wife hit something in the road in her CX5. She didn't mention it until a couple of weeks later she said that it was shaking the wheel. So I took it for a drive - had a noticeable shake at low speed (not nearly as bad more than 45mph) and the classic cupped tire sound. I assume it had a broken belt - noticeably out of round when they spun it up, but the wheel was fine. Alignment was fine as well. Tire Discounters actually contacted Michelin and they replaced the tire for free - because it only had about 3K on them. I know you've been to the tire shop, but did you ask about a discount for a replacement or call Michelin? They may do something for you....although a PITA, it never hurts to ask.