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View Full Version : Why are my tires wearing so fast?



Inspectorlee
11-29-2002, 03:56 PM
I just swapped my Kumho summer tires for my winter tires and noticed something disturbing. Both of the front tires wear worn down on the inside edges. The rear tires were evenly worn. From the condition of the front tires, it's apparent that I have too much toe in (right?). But I don't know what's causing this. My original Firestones had the same problem and when I took it to a shop, they said my alignment was fine. My brother had something similar happen to this Civic and it turned out to be his control arms. So, if my alignment is fine, then what could be causing the toe in condition? My suspension is stock, and I drive a '91 240sx if it helps. Mostly city driving, with no track events at all. What gives?

**DONOTDELETE**
11-29-2002, 05:33 PM
try to get an alignment done at another shop. get a second opinion and see what's up.

i may be wrong; but this happened to me before because the first shop i went to sucks.

dus

Nismo
11-29-2002, 09:58 PM
Negative camber will wear the insides of tires. Lowered ride height could do it (lowered springs or even old springs that have settled). Also, most cars alter the camber of the front wheels during turning; on some cars, a combination of hard cornering and overinflated tires can wear out the insides. Do a search on the Internet for how to read tire wear; there's some good info out there if you search hard enough. Good luck. :)

Q45tech
11-30-2002, 08:10 AM
"overinflated tires can wear out the insides."????????

Over inflated raises the inside [both] edge [s] making [changing the foot print shape] the center of tread tends to wear faster!

Each tire brand [size and type of internal construction] wants some amount of negative camber to optimize handling...generally radials like approximately0.0 - 0.5 degrees negative. Careful as once the static negative goes beyond negative 1.0 degrees the braking distances start increasing.

If you measure the tire tread temperature you will see a dramatic increase on the inside edge [vs camber]...this temperature [result of force] is what degrades the rubber allowing it to wear faster.

The are check and see alignments [whether it is in the broad range allowed by factory] and PRECISION alignments where it is place absoluted in the center of spec...and all sise to sides equal with you sitting in the drivers seat.

Car with soft springs [95%] will change dramatically with drivers weight........align the car to normal driven weight with a half a tank [split the difference] on a Q45 the empty to full changes the rear height by 0.55" this causes a 0.4 degree camber change [More negative].....most lighter Nissans are slightly less. The front is more stable since the front seat changes are near center of gravity and split between 4 springs but still a driver vs no driver can change the left front camber by over 0.15 degrees!

Inspectorlee
11-30-2002, 04:20 PM
I trust the shop I took my car too (my uncle works there). Still, there is the chance that they could be wrong. I run the manufacturer's recommended air pressure too, so it shouldn't be that. Plus, I check my pressure every month so it's not under/over inflated. Any other guesses?

Nismo
12-01-2002, 05:40 PM
"Overinflated tires can wear out the insides [under hard cornering]???"

I know it sounds weird, but when autocrossing, I constantly check the tires. I've noticed that when the front tires are 'properly' inflated, their outside edges wear more than their inside edges. When overinflated, the insides wear more than the outsides. I'm guessing it has something to do with a combination of two things: the increased negative camber while turning and an increase/decrease in tire flex with under/overinflation. Eventually I'll get a good pyrometer, but in the meantime I'm relying on the highly suspect look/touch method. In any case, it was probably an extreme example that I doubt applies to normal street driving where sidewall flex is not a big issue.

Q45tech
12-02-2002, 09:27 AM
The manufacturers placard pressure is only a min max value for best ride with a single size and brand oem tires that came on the car! Any different tire will require a different pressure......which you must calculate and assume responsibility for.

Don't assume that all tires in the same size are anywhere close to the same!