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From: jackh@zehntel.UUCP (jack hagerty)
Newsgroups: net.auto
Subject: Abnormal Rear Tire Wear
Message-ID: <1759@zehntel.UUCP>
Date: Wed, 6-Feb-85 14:56:01 EST
Article-I.D.: zehntel.1759
Posted: Wed Feb  6 14:56:01 1985
Date-Received: Sat, 9-Feb-85 06:47:41 EST
References: <756@rocksvax.UUCP> <4928@fortune.UUCP> <787@rocksvax.UUCP>
Organization: Zehntel Automation Systems Inc, Walnut Creek CA
Lines: 36

> 
> Radial tires should be rotated front to back on the same side of the car,
> according to my Saab dealer.  As for my tires, I did not rotate them
> at all (I know, I'm stupid).  
> 
> -- 
> /Don

Don't be so hard on yourself. In the late '70s when FWD cars were starting
to proliferate, a major tire manufacturer (Goodyear, I believe) did some
long term tire wear studies. They found that if not rotated, the front tires
of a FWD car will wear out in about 30k while the rears (which are "just 
along for the ride") will last at least three time longer, say 90k. If
rotated, they found, the whole set lasts about 40k.

Their reccomendation was to not rotate tires at all if you plan to keep
your car a long time. The reasoning goes like this: 
If you rotate the tires, you'll be replacing them at 40k, 80k, etc., or
8 tires in the first 80k. If you don't rotate the tires you'll have to
replace the fronts at 30k, 60k, 90k, etc., and the rears at 90k. This is
a total of 8 tires in the first 90k, about 12% more mileage on the same
number of tires.

On our Fiat 128 I rotated the tires because I don't like the idea of 
different amounts of tread between the front and rear. As predicted, we
got about 40k to a set. We've since replaced the Fiat with a Saab, and
I've been rotating the tires for the same reason.

On the other hand, I get about 60k to a set of tires on my Alfa which is
RWD. I rotate them every 6k.
-- 
                    Jack Hagerty, Zehntel Automation Systems
                          ...!ihnp4!zehntel!jackh