I ran 15mm spacers on my G for about a year and a half now (19x8.5" +43 wheels). When I took my summers off I had some pretty extreme spacer wear. My rear camber is -2.5 and the front is -1 so the rear wear was more extreme but the fronts also have it even with alignment in spec. How do you guys avoid it? Or do you just go through tires that frequently? It literally cost me an entire season out of my summer tires. Middle and outside tread wear has easily a summer left but the inside shoulder is shot.

Spacer setup:


Going forward, I've given up on spacers and just bought wider wheels with a higher offset for next summer but just wondering why anyone would ever use spacers.

 

You don't avoid it. Expect to lose a season because the inner edge is shot while you still have center tread.

Fitment looks fantastic in that pic, BTW.

 

If you research what a spacer actually does you'll understand it has no correlation with tire wear at all.
The only time it would is if it was out of round or loose.

Remember that any small discrepancies in toe will exacerbate tire wear even at minimal camber. I suspect that your height and living in Canada will wreak havoc on your bushings. One thing we never look at is at suspension bound and rebound, suspension bushings are tightened at factory height and once it hits the floor it puts tension on the bushings, even more tension when lowered. This is why an added tip that most folks dont know is to raise the car in the air with the suspension tensioned and loosen the control arms so the bushings can loose the factory position tension and accept the new position relieving the strain on the bushing and leaving the shock to do the work. This will result in a smoother ride and increase the expectancy of the bushing.

It might "spec" out at the alignment rack however again at that height your putting strain to all of your bushings which is fine on any climate other than snow or anything below or close to 0 C. This means you WILL wear out your suspension faster than anyone living south from you.
I suggest you befriend alignment techs or try to see if a shop offers unlimited alignments and occasionally check your alignment.
On my V35 I had an issue that the rear would sway drastically when hitting a bump even though it specd out I would have great wear on the rear up until close to the end and then in a matter of weeks it would go from 35% thread to bald.

Tires do take time to wear and it's your responsibility to check this wear as it's happening this way you can pinpoint the fault.

The spacers are not your problem.
This is the way.

 

Thanks! I did a lot of research to get that. My new setup is 18x9.5 +35 Black PF01s w/ 275/40/18 tires. Should be nearly identical based on my calculations.

Interesting. So I should have my mechanic put the car in the air and loosen and then tighten all the bushings? Maybe I'll do that when I finally find a rear sway bar.

Alignments are $70 cash at the place I now go to and the guy knows his stuff compared to the other two places I've gone. I've had four alignments in the last 16 months and typically get them annual on all my cars just for peace of mind.

 

The other way around. Loosen the suspension put tension on the control arms then tighten them with while they are tensed.

 

Spacers cause inside edge wear for the same reason as lower offset wheels do - because they increase scrub radius.

You can try and remedy this by using an alignment with a little more toe in.

Ideally, you want to stick with a wheel that has an offset close to/same as stock.

 

Looks like you are right Hugh. This means the only remedy if you want fitting wheels is to toe in slightly.

Op your car is not wearing tires while going straight, your wear is coming from your turning.

 

It happens when going straight too.

The effect of spacing out a wheel is that the wheels will toe out from road resistance, bumps, etc.

Think about it like this...
If you were to put your arm out a moving car....
The further out you stretch your arm, the more leverage the air resistance has on your shoulder (where your arm attaches) It will push your arm backward and it will point outward slightly as it pivots backward.

Same effect when you start spacing a wheel away from the suspension attachments that control alignment.

Maybe not the most perfect analogy, per say. But its something that most people can relate to.

Scrub radius defines that "lever" length as well.

You're also loading the inside patch of contact more than the outside. You're spacing the attachment of the wheel further inboard in order to push the wheel out.

 

Toe affects tire wear far more than camber.

All other things being equal, I don't think the spacers are to blame.

P.S.

Is Mints still in business? I remember going there when I was in Buffalo for work back in the mid-to-late '90s.

 

Do some research on scrub radius like I did and you'll understand Hugh is right. In fact it's it's one of the most over looked aspects.

How many folks lower their cars on stock wheels and keep that stance? not many and those that do for the most part use spacers
You have those that go through their entire suspension setup with multiple alignments to tackle this wear and it still happens.
What most dont get to see is that this might not happen on OEM wheels due to this radius.

Hugh, being that the coupe came with a staggered setup makes me wonder if you went with a squared setup on a coupe if you would see this. I suspect no being that the sedan and coupe are have identical chassis components apart from the shocks and springs.

 

Scrub radius is dependent on alignment angles and wheel offset.

As far as what you control with wheel options....just keep the offset reasonably close to stock. Offset determines the wheel/tyre centerline.

I have never measured the G37 scrub radius. An educated guess tells me its designed to be slightly positive from the factory. But I could be wrong. Next time I have mine in the garage, I'll see if I can check.

 

So my new wheels at +35 should wear slightly worse than stock. I was thinking that since the location of the tire starts further in than stock, it should wear about the same as stock. I will definitely have the alignment shop toe in slightly when I'm there in the spring.

How do I loosen the suspension but put tension on the control arms?

 

The location of the tyre centerline is further OUT than stock when using a 35 offset. You're pushing outboard with a lower offset.

The word for what you're trying to do to your bushings is to clock them. You need to do that any time you significantly change ride height.

The easiest way is usually to loosen all the bolts related to pivoting bushings and then drive the car on a drive up lift (like an alignment rack). Then tighten all the bolts up.

If you're doing this at home...lift the car onto jackstands and then use a jack or other method to push the LCA up so the whole suspension sits at the same angle as it would be when the car is on the ground. Then tighten.

Try youtubing "clocking bushings".

 

Quoting for how much great info is in this comment.

 

This is awesome. Thanks guys! So the alignment shop should be able to clock the bushings easily enough then. I'll describe this process if they don't know the terminology.