FW: tire size differences

[Livolsi, Stephane]

I suspect this is going to be one of those topics.......

These comments should be qualified that they only apply to vehicles with
more sophisticated torque sensing diffs.  An 86 5ktq (with diffs not
locked), for example, would not be damaged by running different size tire.
The differential would simply do it's job of allowing different tires to
turn at different speeds - that's what it's there for.


Stephane

> From: 	Marc Sims[SMTP:avarlinqui at hotmail.com]
> Sent: 	June 5, 2003 2:56 AM
> To: 	quattro at audifans.com
> Subject: 	Re: tire size differences
>
> Re below;-
>
> Tell me about it I made the mistake of trying to gradually move from a
> 50mm
> profile to a 45mm, I thought that If I did the front first and then the
> rears a month later when I had the cash It would be OK, BIG mistake, the
> car
> was crabbing and jumping along the 500yds of road back to my house.  I had
> to spin the car round and get the remaining two tryes done before my diffs
> went bye bye.  Other than that actual tyre wear is almost non existent,
> average 14k on a set, my old coupe q manged 16k on one set and trust me I
> wasn't the sort of driver to go easy on them.  This is compared to the
> nasty
> Vauxhall Calibra 4x4 that got about 4k out of a set (permanently locked
> diffs, i think).
>
> Marc S
>
> >the problem with running different sized tires on an all-wheel drive
> >vehicle (like an quattro) is that your expensive gizmos that sort out
> >the torque to the various wheels get really confused by the variances in
> >rotational rates at each wheel. then those components tend to quit
> >working and/or self destruct. the only way to insure that the tires are
> >all the same size is to run the same brand and model tire at each wheel.
> >although the sizes themselves are standardized, the diameters of
> >different manufacturers tires can vary within certain parameters, and
> >this variation can be fatal to the aforementioned components. i hate to
> >be the bearer of bad tidings regarding this sort of failure to a
> >customer, but then again, it's not my car, and i didn't do it to it. i
> >will fix it, though, and it is not cheap. the tire education is included
> >at no extra charge. marc
>
> _________________________________________________________________
> Express yourself with cool emoticons - download MSN Messenger today!
> http://www.msn.co.uk/messenger
>
>