Tires: Tire Wear & Shimmy, tire pressure gauge, proper inflation

Question
Barry, I appreciated the answer you gave on the 1010tire forum & wanted to ask another. I don't know if you frequent the forum much but know that AllExperts will notify you if someone asks a question here. It's nice to see that I get to ask a 'real' expert too & not someone who just thinks they know lots.

With my new-found knowledge of tires (albeit at a very rudimentary level), I checked over my Mom's car. Looking through her papers, she hasn't had her front tires changed since '97 & even then, they were used tires. Her back tires were replaced with new ones in '03 & the tread is excellent still. She drives little.

Front tires have wear on the outer edges of the tires which indicate under-inflation (right?). Her car has a noticeable shimmy or vibration that can be felt driving between 35-50 kph. I checked her tires pressure & they're inflated to what they're recommended but I don't have a high quality tire pressure gauge. Only those simple ones so don't know how accurate they are. I told her I'll take her car in to get good used tires put on the front.

Is there any conditions that would cause the front tires to wear on the outsides even with proper inflation? Would it explain the shimmy in the steering? Or is it possible the older tires were already starting to wear more long before? The shimmy started a year or two back & nothing has been found for the cause but they've never bothered checking the tires for a possible cause. The tires are the correct size for her make & model too - a 91 Chrysler Imperial.

Thanks for any help or suggestions!  

Answer
Judy,

First, how did you figure out that I frequent 1010tires? (which I do every day)

Second, the wear on your mother's car is probably a combination of camber and toe in, which sometimes results in an irregular wear pattern, that in most cases causes a noise or a vibration.  So an alignment should be done as if this is not fixed, the problem will come back.

Third, I don't recommend purchasing used tires.  You don't know if proper maintenance was performed on them, so there is an elevated risk of failure - meaing someone disposed of them for a reason, and you don't know what that reason might be.

Hope this helps.