I've been seeing some people talk about this. I have unlimited alignment with Firestone which I want to get done soon so I would want to tell them to adjust the toe. What should I tell them? I have the RCF/GSF bushings installed already though, but I would still like to maximize my tire wear.

Thanks

 

Zero camber and zero toe, front and rear, for max tire life.

 

Going to Firestone tmrw, they say they adjust it to "factory specs" so I'll see what it's at tmrw

 

The inner wear issues will happen if you use zero camber and toe, or at least, apparently. What OP was asking was if there's a way to use the alignment to mitigate wear... which, in my case, seems to have worked.

I am running everything stock except for .05 deg of toe. The slight toe-in helps to combat the toe-out that happens under braking, or at least, that is the theory.

I will measure my tread depths again tonight and post back here. It's been about 12,000 miles on my tires now.

 

Factory specs are too loose! Tell them what you want. Opposite sides must be equal, same setting.

 

thanks, i will try this then, keep me posted on any additional adjustments

 

Well here's what I got tonight. Measurements were done with an analog tread depth gauge in 1/32".






Note:
I just replaced the RR tire about 2 weeks ago due to a bubble. FL tire was also replaced about 3,000 miles ago due to a bubble. Factory tread depth is rated at 9/32" front and rear.

As you can see, the tires that weren't replaced were the FR and RL. They were put on at about 21,000 miles, and the car now has about 33,400 on it. So these BFGs in general seem to be decently long-wearing tires.

I'm using a simple analog tread depth gauge, so it's probably not very accurate. I estimated the half-32nds.

I'd say the inner wear on the FR is pretty insignificant compared with what it would be if I was still on the stock Bridgestones with 0 toe. 1/32" isn't really what I'd call "excessive".

edit: So after I posted this I happened to think about how the innermost "lip" of the tire might be wearing, so I plan to take a look at that, with my eyeballs , this morning.

 

I just checked the very edge of inside of the tire on my way to my desk this morning, and it looked pretty much normal to me. Looked about the same as the outer part of the tire.

 

there's no avoiding the inner tire wear. par for the course on this class of car. Porsche, AMG, ///M etc all experience it too. if any car has even a shred of performance ability, you're going to get that kind of wear to some degree or another. it's baked in to the cake.

BMW designed this philosophy in the 1970s. then the rest of the industry caught on. There's deep engineering behind it and the reasoning for it! It's just lexus owners aren't really used to it. but it is a necessary evil of performance on the street.

you can zero out toe to mitigate though. but zero toe is not ideal for straight line stability which brings you back to square one.

Honestly i'd just get the GS-F bushings, buy some firestone firehawk indy 500s and call it a day. there's going to be no getting around the inner wear on this car. it's baked into the cake. it's a done deal.

This is what you all signed up for when you chose a car that was designed and engineered to compete with and take down the ultimate driving machine. you've joined that club.

 

The IS, from the factory, has the unfortunate combination of soft lower control arm bushings and terrible OE tires in terms of treadwear. Sure, this leads to a better balance of comfort and handling ability, but this "German engineering" doesn't need to be put on a pedestal. It leads to the common problem we all know as the 3IS's famous inner wear. This problem should not be considered a badge of honor. Similarly, I shouldn't feel proud that my non-F-Sport brakes are squealing due to a poor brake shim design.

If you want me to take a photo of how my FR tire is wearing after 12,000 miles to help support my case I could do that. This morning I was running a little late to a meeting so didn't have time to do more than quickly glance at it, but could do that later. These tires have a year's worth of daily commuting and one very spirited run through the Ozarks under their belt, and seem to be wearing pretty much evenly - certainly significantly more so than before I had the custom alignment done. Again, all I did was keep everything Lexus-recommended except for adding approximately .05 deg of toe-in at the front.

Oh, and zeroing out toe to mitigate inner wear doesn't make sense. If the tires toe-out during cornering and braking, you'd need to combat that with toe-in, not zero toe, as is the recommended setting from Lexus.

I'm not saying the inner wear isn't an implicit problem in the 3IS lineup. It definitely is. That said, to state there's nothing that can be done about it short of changing my bushings seems like it may not be true.

edit: And here is my passenger-side front tire.

 

Maybe it's just camera angle, but you do appear to have a bit more wear on the inner, especially visible in the smaller tread blocks.
That is where most of the wear appeared on my tires, before changing to the FIGS bushings.

 

Thanks. When I got home just now I measured the center part of each outer and inner tread block to see if it's measurably different. Warning, you're about to see all the junk stuck to my tires from the drive home.

I was starting to doubt the alignment strategy after seeing your post, but now I'm fairly confident that either A) the lighting was to blame or B) there may be a difference, but a small difference that is probably better than stock.


Outer tread block appears to be about 5/32".


Inner tread block also seems to be about 5/32".


So while this tool isn't exactly 100% reliable, I think it's close enough to say it's not as big of a difference as it would be otherwise. When I got to 21,000 miles on my car's original tires, the inner part was almost bald, whereas the outside still had 6/32".

 

Not really related but when I was 1 month away from lease return, my reading was at 4/32 with 17k miles on the vehicle. I babied the car for the next 500-600 miles because if I'd hit 3/32 I'd have to pay lol. I also was on the stock tires which I don't believe you are. Never understood why the car ate through tires.