2000 Miata tire wear, irregular, what to suspect?

The last alignment was in 2001. You don't remember the final settings. (Too bad, since you cannot compare them to where they are now.) The front outside wear may be nothing more than cornering wear. Throttle oversteer may be due to the alignment changing. Inside wear on the rear tires may be alignment or load.

In short, get the car aligned, record the settings before and after. The factory alignment specs tolerances are too wide. "Preformance" alignments will make for sensititive steering. Alignment specs on miata.net range from sedate to extreme. Your choice. Tire pressure will have an effect on both handling and wear.

Do a new alignment and post the old and new numbers to satisfy our curiosity.

What were the wear characteristics on the previous two sets?

Increase negative camber to take wear off the outside edge?

Decrease toe. Increase camber if evidence of wear on outside edges.

Seems easy. You just told us that the thread areas you drive on are severely worn. If you no longer have good rubber on the road, you do not have good traction.

Interesting in view of the high pressure.

Well, that is already noted in the product reviews on miata.net.

Not clear to me why you need the toe then. Though I believe toe in at the rear does help stability. Lannny's alignment may be a better choice.

Leon

For better or worse-- As my 99 came off the rack 12/31/04 (180lbs drivers seat) ~69,000mi Adjusted to more or less center of stock spec. Fender to axle center distance NOT adjusted, seemed to be within limits of measurement without exactly locating center of axle and exact spot on fender to measure from.

15" Toyos T1-S (Whichever it is) 29psi my gauge Left Right

-0.4deg Camber -0.3deg +/- .1deg dither

6.2deg Caster 6.2deg 6.2 max attainable this car both sides 0.06in Toe(in) 0.08in +/- .01 rack dither 11.6deg SAI 11.8deg 11.2deg incAngle 11.5deg Cross camber -0.1deg +/- .1 rack dither Cross Caster 0.0deg " " Cross SAI -0.2deg " " Total Toe 0.14in +/- .02 rack dither

Rear Left Right

-1.0deg Camber -0.6deg

0.03in Toe (in) 0.02in Cross Camber -0.4deg Total Toe 0.05in Thrust Angle 0.01deg

At these sett>

Don't do anything until this is fixed.

How the hell do you get Torque Steer on a rear wheel drive car? You guys getting special rear wheel steering MX-5's in the States? Or you drifting the car EVERYWHERE? ;)

I will soon when I get new tires.

However, I do recall that they could not achieve all of the alignment specs I wanted (as I posted) because the car was at the limit of adjustability. I think mostly they got as much neg. camber as they could which was less than what I wanted on at least one corner.

Orig. tires were whatever 2K cars came with Yoko's... wore relatively evenly but rear wore faster than front obviously. Second set wore dead even (Pirelli P7000's I loved!!), rear faster than front.

I think with prev. alignment it was at the limit. But the alignment could have drifted.

yep.

High pressure does not help too much with the flexy/slow/vague feeling. The tires will take up to 44psi and I've pumped them that high and it just loses traction beyond my chosen pressure. Below ~33 they are very flexy and basically feels like I'm driving a mini-van.

Yeah, well the reviews on miata.net were not very uniform when I got these tires. Choices are slim for really terrific 14" tires that will last much more than 10K miles, or cost much less than $100 each, nevermind both, and really nevermind rain performance. Next time around I guess I'll give on one or the other parameter. For the $36/ea I paid for these tires I didn't expect much.

That's the main thing I'm tryin to get out of this discussion, what alignment specs SHOULD I go with? At $60/ea it's not something I want to have to go experimenting with all the time. Basically I'm looking for go-cart feel from the car as much as possible. I could care less about whether it's twitchy on the freeway. And I need the tires to wear evenly if I am going to put sticky rubber on there that wears fast.

Seems to me that you have conflicting requirements. If all you care about go-cart "feel," then pumping up the tires will have the biggest effect, and the alignment will be almost irrelevant. If you want to autocross, use the special alignmnent, gumball tires, and appropriate (pretty high) pressures. If you want good performance on the street, and reasonably even wear, use the stock alignment and pressure, and performance street tires.

Note that until you have driven racing tires on the highway, you might want to be careful about saying that you don't care about twitchiness. A set of Yokohama A032R tires will cure you of that theory pretty quickly...

Read my alignment page. Don't go to an alignment shop until you understand it (but feel free to ask questions here). The important points:

1. For even wear, the alignment must match YOUR driving habits. I offer suggestions for a starting point, but there's always a terminology issue: what's "brisk" driving to me may be suicidally fast to you--or vice versa. I spent about 0 fine-tuning the specs for my own situation, but if you're lucky it will make you smile the first go-round.
2. Observe the order of adjustments in my article. Both sides must match, max variation 0.1 degree.
3. If it ain't ballasted, it ain't a precision alignment, because you don't know how it will change when you sit in the car. But it *will* change enough to change the basic feel of the car.
4. If the technician gives you any crap about custom specs or excessive wear, just leave immediately and keep shopping until you find a competent garage. Life is too short to argue with fools.

Rotate performance tires at every oil change (3000 miles), all-seasons every other oil change. I got 15k wonderful miles from a set of

195/55-14 T1-Ses, driven pretty hard. At 28 psi, they wore evenly across the tread, and all hit the wear bars in the same month.

Go-kart feel: you can get that easily from a Miata, though you may soon decide it was a stupid mistake. All it takes is giant swaybars and stiff springs/shocks. However, if you actually want good handling, tires and alignment are the place to start.

Seem to me your alignment was fine. If your latest tires float all over the place, I would just ignore what their wear pattern is.

Based on the other tires, personally I would guess the problem is with the junk tires yielding so much their edge is exposed. In short, if it were me, I would replace tires, not alignment.

Actually, I was talking about good straight line grip. All things being equal (they usually are not), rubber works better the lower the pressure. But on thinking it over, the junk tires probably help on the straight line since they are flexible enough to completely ignore the camber of the wheels and meet the surface flat. So I am no longer surprised.

Be careful with the numbers. Apparently, Ziex tires with slightly different numbers are very different, believing the reviews.

Frankly, I think you are not going to get a satisfactory answer on the question as posed above. At least I cannot imagine anyone being able to analyze the issue and produce the optimal (versus an) answer.

For what it is worth, my non expert take on it is:

1) You are not going to get any real life time out of performance tires. To go for a "Save the Tires!" alignment with performance tires you get the worst of *both* worlds: lousy handling and only marginally improved short life span. 2) Getting a *good* performance tire, (not the ones you have now, but don't ask me for a recommendation), you need to make a decision whether you want handling or performance.

a If you want handling, look at Lanny's page. I just looked at it myself once more, and I am a believer. They are technically sound and agree with my own impressions. Note that I am *not* a precision driver by any means; I am not going to argue about a few tenths of a degree.

b If you want long tire life, set camber and toe to zero and drive like you grew up in Tallahassee.

You might get a meaningful answer in this group from someone for the question "What is the best tire and alignment to get the best street performance, blast the cost?", or "Can you tell me a tire that lasts many miles gently commuting, and good rain and straight line grip when needed in an emergency?" but not on "Can you give me alignments and performance tires that produce incredible grip while lasting a long time?" Any good answer to the last question is *equally* bad, since what you gain on one part, you give up on the other part.

Leon

Good points.

FWIW I can heartily recommend these Falken Ziex tires for the tire part of your second rhetorical question... lasts many miles gently commuting, good rain and straight line grip when needed in an emergency.

Really the car was the way I wanted it with the Pirelli P7000's at 35psi front and 34psi rear and the alignment I had done when it was new. Unfortunately those tires are not available any longer and it seems decent tires are hard to find in size to fit 14" Miata wheels any more.

So I'm inclined to believe the advice that the tire wear pattern is irrelevant indicator of alignment. However I will plan to read up (again) Lanny's page and have it re-aligned again when I get new tires just for known-quantity sake.

I still haven't finalized my new tire choice but I'm leaning towards Falken Azenis 195/60-14's or Toyo T1-S 195/55-14. I'm presuming I can get the kind of fun feel I want from the car with either of these tires, might get more miles out of the Toyos but might get more absolute grip from the Azenis... Anyone care to comment?

Thanks-

Not exactly. Tire wear patterns are very good indicators of too much toe, or of camber settings not appropriate for driving style. Aggressive cornering needs large negative camber.

That last part is true. The Azenis is very stiff (also noisy and heavy), and steering input translates instantly into directional change. The Toyo is much softer and one of the lightest tires available, with a little lag between turn in and bite, which most drivers adjust to and stop noticing in the first 30 minutes (but which some drivers hate and never get past). The Azenis feels like a crude but thrilling amusement park ride; the sophisticated Toyo rewards anticipation and smoothness, and delivers an unbelievably-silky ride. In 14" sizes, the Toyo costs about 60% more, but will last twice as long (and avoid half the mounting/balancing charges). The Azenis is a terrific autocross tire, but I hear that it tends to melt in track use.

The Azenis is an axe, the Toyo is a scalpel. Either will raise the limits of a Miata way past what you can use prudently on the street. The Toyo will also do it in the rain.

That "little lag between turn in and bite" is exactly what I can't stand the most about my current tires.

So... do you have any experience with the Pirelli P7000s on a Miata (185/60-14)? They were quick enough response for me. The OE Yokos were not.

When they first put on these Ziex tires I have, I thought they had forgotten to tighten the rear lug nuts. That's how bad it is. I once had a 240Z with completely blown shocks in the rear. It felt just like these tires make my Miata feel.

From this description, it sounds like the Azenis is more what I'm looking for. I kind of want the thrilling amusement park ride. Is there a tire that's in between? "silky ride" does not sound like what I'm after.

I'm not racing. Just trying to perk up a commute.

You mention this about rain. Rain performance on the Azenis gets very mixed reviews. Some people seem to say they're useless in rain, others say they're great in rain. I have heard they're useless with standing water. This mixed review on rain performance is precisely why I did not buy Azenis tires instead of the Ziex I have now. Do you have direct experience with rain perfomance of Azenis tires on a Miata? I don't need a tire that will deliver its top performance in the rain, since (other than the past couple of months) it only rains infrequently in Austin. But I do need a tire that I can safely drive in the rain. The main thing that drove me from the Azenis was the frequent note that it's incapable of handling standing water, and I HAVE to make it through a low-water crossing on a regular basis (once a week or so) and when it does rain in Austin, we get a lot of "ponding" on the roads so being able to drive (carefully) through standing water is an absolute MUST and that's why I'm not driving on Azenis tires at present.

So is there a tire that's in between? More amusement-park than the Toyo, less hydrophobic than the Azenis? Or are these fears about the Azenis a myth, or only an issue on FWD cars (seems the reviews of bad rain traction seem to also relate mostly to FWD cars...)?

Dang this has turned into a tire selection query. But I have resolved to have the car realigned when I get tires, using your specs as a starting point and tuning the toe myself as you suggest on your alignment page. So hopefully soon alignment will be a non-issue.

The Toyo lag isn't the same thing--it's not a mushy feel. They definitely bite, with a tenacity the Ziex cannot approach. I'm not sure what's actually happening, but it feels like a small amount of slack being taken up in the sidewall (I think it's really the tread belt). If you turn in smoothly and progressively, and a little early, you'll probably not notice any lag.

Don't underestimate the advantages of a smooth ride--the T1-S soaks up tar strips that cause cowl shake and rattles with other tires. They also maintain amazing grip on loose or broken surfaces, like gravel, sand or chunking asphalt.

I have never driven the Azenis in the wet in a Miata, though the track was damp when I did the Rev It Up thing in a 6. I expect they'll stick very well until the water is deeper than the tread groove (only 8/32" on a new Azenis), but will plane readily at higher speeds or more water. You should be fine as long as your water crossings are slow (25 mph?) and cautious.

OTOH, the T1-S sticks so well it can be made to squeal on a wet road.

Join your local Miata club and beg rides in cars with each tire. These are two radically different solutions to similar problems, and each makes its own compromises. Decide for yourself which is best for you.