Flite

The front of my car is supposed to be aligned to -1.5° camber with 0 toe. It's lowered about 2", nothing ridiculous. I'm not a "get-yo-fitment-hellaflush" kinda guy. This is after about 4000 miles of easy street driving. Something is seriously shredding the inside of my tires. The rest of the tire looks brand new. Any thoughts? Alignment machine off maybe?

My rear tires, which are at -2.5° camber with 1/4" total toe in, look brand new.

boredom

if you find out, please lmk. i have the same issue on my car. the rear tires look new and are over a year old, the passenger side is ok, but the edge of the driver side is bald as fawk.

CRANKWALK

its crazy how it looks like its right up to the factory tread pattern/groove... faulty tires perhaps?

also, looks like they are choppy on the inside (from looking at the dark and light spots)
do they make alot of noise, or make the steering wheel shake?

Flite

I doubt it's a tire issue. There has been no shredding, chunking, or anything like that. When a tire is worn nearly to the cords, it's common to look a little uneven like that. They drove outstanding and were quieter than the tires on my wife's RL. I'm pretty positive it's an alignment issue.

The only thing I can think of right now is that maybe I need to actually dial a little toe in... back in. I'm running 0° in the quest for steering feel, and it seems to work great for that. The current alignment really livened up the steering compared to how it feels at stock alignment specs. It's not worth it though if it means I have to change my tires more often than my oil.

The Guy

I think you need to toe in a little. Im not the greatest with alignment issues, but it makes sense to me. But (maybe its just me), i feel like the tire is running a more drastic camber than -1.5. It seems to me that -1.5 would wear more of the tire than that.

Fabrik8

That's the key phrase right there. The combination of that tire wear and what you're saying about steering response add up perfectly.

First of all, realize that static toe and dynamic toe are different, so toe on the alignment rack isn't going to be the same as toe once you add steer angle.. I don't know anything about the steering geometry of that car (especially things like Ackerman geometry) so I can't say what the toe change is with respect to steer angle, but it could be adding up to a lot of tire load and scrub especially when lowered.

Anyway, it sounds like you've gone more toward a race setup (static toe out or zero static toe) instead of a street car setup (static toe in) and you're seeing the tire wear problems to prove it. So the easy cure is to add some static toe in and decrease turn-in response but also decrease tire wear and decrease ultimate grip. The cost of tires doesn't make the extra steering response a worthwhile tradeoff for a street car IMO. Basically if you have toe out (or zero toe, all depending on steering geometry) you're starting out with some slip angle as soon as you start to turn, so the inner tire is loaded sooner than with static toe-in. The load then transfers to the outside tire, and then you're effectively working the inner tire pretty hard. Adding that small amount of slip angle preset is what is killing your tires though, because you're dragging the inside tire at a funny angle all the way through the turn. Going back to the steering geometry, anything that increases the toe with steer angle will obviously also increase how much that inside tire is getting dragged throughout the turn.

If I'm looking at the picture correctly, the inside tread blocks are worn more at their ends (where they taper to a point) than that the beginning (where they are widest) which usually means that they are getting pulled sideways where they have the most compliance. The greater wear on one side of that major groove versus the other side would point toward the same thing.
If it was camber wear, the wear would a lot more even across the face of the tire because the vertical load would be more even (across the face of the tire), and there wouldn't be the change in wear across the groove or the tread block tapering (I don't want to call it feathering because it doesn't really look like it).


Sorry, this post turned into the "Drink beer, think a little, edit post... Drink beer, think a little, edit post..." type of rambling. The editing will now stop, as I just emptied the bottle.

marlinspike

Drag your hand across the top side to side. If it's toe, one side will feel sharper, if it's camber, they'll feel the same.

Fabrik8

That doesn't work very well with tires that have such big tread blocks because the tread blocks don't deform nearly as much as smaller tread blocks.


Or with slicks.

marlinspike

Hmm....would a Toyo T1R fall into the big tread blocks category? My left front wore off basically the outer 2cm of tread of the tire. I don't know if it's still doing it post-alignment, but the alignment adjustments we made were very minor. I'm thinking it's camber, but given the localized nature of the wear and what you said maybe not?

Also, is it just me, or do OP's tires have a crazy tread pattern?

Fabrik8

Dunlop Direzza Star Specs I believe.