Billman250

A little front toe in makes all the difference in the world when it comes to inside tire wear on the S2000. Regardless of what you see the need for, your experience with your numbers, or whatever else you read on any forum or this one for that matter.

I've been aligning cars for 25 years. I know what the number mean, and their affects on the tires.

These setting have saved every s2k I have ever aligned from typical inside tire wear.

SpitfireS

This picture I took 10 mins ago.
Yokohama Advan AD08, start usage - new - at 201690 km, switched to wintertires at 220840 km.
Total km on tires today (still running the Continentals due to cold mornings) = 19150 km.
So.. what is the inside?

Yes, it is the right side.
It does wear on the inside, but not that much as far as I'm concerned.
The "dip" on the upper right tire is the groove of the profile showing, not extra wear.
Alignment at the time - and still is - UK-spec (with 1.1 degree front camber actually) and zero front toe.
And I'm happy the way it is driving - even on winters.
Can't wait for the morings to get a little warmer so I can get the AD08's on again.

edit: these are the fronts 205/55/16, just want to make this clear.

ZDan

You're right 99.9% of the time. But you're wrong on this. Zero toe is fine, 0.07 degrees total front toe is also fine. The difference between the two in terms of feel and wear is going to be something approaching nil.

In any case, specifying .03deg to .04deg per side to the alignment guy is just going to annoy him. I ask for zero toe, fully knowing that I'm going to get something between +.05 and -.05 total, which is fine with me.

0.01 degrees is .004" at the tire tread. There's just no good reason to specify toe down to that fine a resolution. It will usually change by more than that amount between alignments anyway.

I've always run max front camber, or about -1.25 degrees, with zero toe (or rather, +/-.05 total), and never have had an issue with inside tire wear.

Toe is very important. But .01degrees is way finer an increment than necessary.


If you've ever done back to back to back testing of front tire wear on the same car at 0.00degrees front toe-in vs. 0.07degrees total front toe in, on the same tires, driven on the same roads at the same speeds, same pressures, same temperatures, I'd be interested to see the results. But even then the change in wear rate is going to be less than what could be attributed to error.
If I *had* to bet, my money would be on zero toe...

spets

How would toe in decrease inner tire wear? Any amount of toe is going to start scrubbing the tire which equals more wear.

All toe in will do is scrub the outside of the tire to even out the camber wear on the inside of the tire and make it appear more even. I highly doubt you actually get any more life out of the tire.

For what it's worth, I ran star specs on exactly those alignment settings (with less toe in the rear) and had perfectly even tire wear. Then I switched to RS-3s and the softer sidewall wore out the inner shoulders of my tires more than the outers. The tire you run can have as much of an effect on the tire wear characteristics as the alignment setting.

Mr Apex

Weight in the car makes the front tires toe out. So on the alignment a little toe in is dialed in to make up for passenger weight.

Gernby

I've always run as close to 0 front toe as I could get, but have always worn the inner shoulder of my front tires WAY faster than the rest of the tire. However, I decided to go with .16 degrees total toe-in (high end of OEM spec) for the alignment I just got, since I'm now running non-staggered. Also, when I was under the car examining the suspension geometery, it's clear that the toe will change as rolling resistance increases. As the car is travelling forward, the front wheels get pulled slightly back by the rolling resistance of the tires and bearings. IIRC, the steering rack is slightly behind the tie-rod ends on the knuckles (which are in front of the front wheels), which would mean that the wheels would automatically toe out further with more rolling resistance.

ZDan

What camber? At ~1.25 camber, my fronts wear evenly at zero toe, and I get on the order of 20-25k miles out of Star Specs. On the Z, with 2.5 camber, zero front toe, tires wear evenly (~5% of miles on track, though). IMO, you're just going to scrub more and reduce tire life. It's entirely possible to get more even wear and a greater wear rate, too! Weirdly, I've seen people say that they'd rather have even wear and shorter tire life than asymmetric wear and longer tire life. I don't worry about asymmetric wear (but then I don't get much either, less than 2/32 difference inside/outside on the rears at 2deg camber at end of tire life, fronts even).

Rolling resistance is fairly constant with speed, it doesn't increase. At the high end, rolling resistance on tires set to zero toe will be on the order of 11 lb. per corner on an S2k (750 lb. load per corner * .015 RR coefficient). That's a *very* small force relative to maximum braking forces. It's not going to alter toe appreciably. That said, any amount of toe-in will increase drag force considerably, so the more toe you run, the more dynamic toe-out you induce, but still goign to be small numbers...

For max tire life, my money's still on zero toe.

darcyw

i'll throw some argument in here too.

My AP1 has 1/4 inch total rear toe in. It most definitely has helped stability in addition to -1.7 F camber and -2.0 rear camber. In the AP1, don't be afraid of rear toe in- check the euro alignment values if you want some confirmation.

oh, and tires are disposable to me so if i only get 2 summers (5000 miles/summer) on a set of star specs, i'm happy.

darcy

ZDan

Be afraid of too much rear toe. Sucks for everything. Creates way more INstability in traction-challenged conditions and/or any asymmetric undulations. KILLS tire life. I found more linear handling, VASTLY increased tire life, better turn-in when I wanted the car to point, but less spooky weird dancing around in a straight line in less than perfect conditions.

I went from 0.64 deg total rear toe (0.28", ~1.4 after two track events, due to the rears being prematurely corded (which led to the car being practically undriveable for myself and co-driver for time trials at the 2nd event on them). Went to 0.15 degrees total accidentally (asked for .15 per side), found the car to be WAY more predictable and fun to drive at the track, and got ~3x greater tire life. Using the tires' lateral grip capabilities to pit them against each other just doesn't work well for handling characteristics or tire life.

I've run the gamut of rear toe settings, and even inadvertently did a blind test. Alignment bolts weren't adequately tightened, handling and tire life both went straight to shit on the track and on the street (particularly wet handling, the car would be all over the place down the straightaways but then wouldn't turn in for ANYTHING entering corners at the track, on the street I was crippled in downpours, reduced to ~10mph less than traffic) until I finally checked the alignment and found rear toe had crept way *way* up (1deg total, obviously way outta line, but then again the infamous UK spec gives a range from 0.67degrees to 1.33 degrees!). The UK spec is almost certainly erroneous, as it gives exactly TWICE recommended rear to vs. the US spec of 0.32 degrees to 0.64degrees total.

In my experience on the street and track, adding rear toe for "stability" simply doesn't work. Kills straight-line stability, but also kills turn-in pointability.

Short version: I hate rear toe. It sucks for everything. Really.

Gernby

Rolling resistance is more of an issue with some tires than others. I measured a 6% decrease in torque across the whole RPM range in 3rd gear when I switched from Sumitomo HTRZ II's to Hankook RS-3's using my CAN dyno. I believe that's over 50 lbs of force pulling the front wheel backward (toeing the wheel out).

The last front tires I replaced were Hankook RS-3's, and I probably got 15K miles out of them. However, I had to flip them over on the wheels to move the heavily worn inner shoulder to the outside of the wheel. I had very close to 0 toe with about -0.7 degrees camber.

That said, we do have VERY, VERY abrasive (and grippy) concrete roads, which I'm sure decreases tire life dramatically.