Wear patterns, alignment, and pressures.

[olddognewtrks]

I have a lot of info here, and a few questions.

I have an '03 Mazda Protege' 5. I'm coming up on 50,000 miles with the OE Dunlop SP Sport 5000 tires, 195/50-16. I'll be replacing them soon. Mostly highway miles, often with nearly 600 lbs of me, wife, dog, lugggage, coolers, etc. The suspension squashes down a bit, and the tires are wearing early on the inner rib, with some minor cupping. I have consistently inflated them 4-6+ front, 2-4+ rear.

When I replace them, do I want my alignment guy to set the camber to zero with a medium load in the car?

Would backing off the pressure a couple of PSI allow the belted tread to lie/roll flatter, versus a firmer, less yielding shape that puts more pressure on the edge of a tilted tire?

Lastly, any recommendations for a replacement tire?

Thanks ahead of time.

 

[Trucku]

How often do you rotate them?

 

[bdcardinal]

i think camber on that car is non adjustable. wear on the inside that does not extend inward is usually from toe out.

 

[mazduh30]

You stated "minor cupping", when did you last check the balance? Also cupping can be caused by tired shocks/struts, loose parts, faulty wheel bearings.

 

[olddognewtrks]

Sorry guys.... Rotation same side/front-to-rear every 6-8 thousand miles, balance every other rotation. Cupping is not really accurate; it was more of a stepped, "ramps-in-a-row" pattern that repeats with each shoulder block. I managed to even it out quite a bit by doing an X-pattern rotation at about 34 thousand miles (they're non-directional). Now they're just mostly worn out on the inside rib.
These tires are close to retirement anyway; I'm primarily hoping to avoid problems with my upcoming replacements. Thanks again, all.

 

[wantin150]

That sounds more like "feathering" which can be cause by high speed cornering.

 

[mazduh30]

If the feathering wear is across the thread with raised tread block edges, most likely toe setting. If you are driving aggressively in corners, ask the alginment shop for more neg. camber.

 

[alreadygone]

Ramps in a row is simply from not changing direction. Alignment is allways a good idea with new tire purchase, but get a nondirectional tire and X two, move other two different end without X. Doesn't rally matter which end is Xed long as it's allways the same end. DO change directon of rotation regularly though!

Bob

 

[ewetho]

Mazda should have the rotation done with he front tires going straight back to the rear axle and the rear tires crossing to the front.

Sounds like you may have a bit of a toe problem. Also make sure the ride height is checked. Depending on strut mounting design you should be able to Camber altered if it is needed. Check for and minor strut or suspension problems as well.