>If you put a wide tire on a narrow rim you get the tirewalls to protect the
>rim from being damaged, probably better load capacity and better flotation
>on sand, mud and snow with low airpressure ( ok, ok I�m an offroader too).
>The drawbacks are that it allows the rim to slightly move around in the
>tyres which feels like innacurate steering, sliding when cornering and
>sensibility to sidewinds.
>It�s not as much a fact as a feeling and could often be cured by raising the
>airpressure but then you�ll have a bumpier ride
>With matching or narrower tyres on wide rims you get the sidewalls stiff
>which does the opposit to the above, you�ll get a accurate steering and so
>on, compare with a sportscar ( no not some streetrodder, NASCAR or INDY - or
>a Porsche ) and you�ll see that they have almost no rubber outside the edge
>on the rim !
>Then, if it�s on a Vanagon, this is off small importance since you never put
>that much G-forces on your wheels

Wanna bet??

>but you should try to match wheels and
>tyres, make a decision about which is the more important - loadcapacity or
>soft ride - and buy tires according to this if you�re allowed to by the laws

Corollary: fit tires which do not bag (too wide for rim) and do not
taper inward from the rim to the tread (too narrow for rim). The
lower the tire profile, the closer the fit necessary.

Tires too narrow CAN come loose at the rim, allowing leaks. Tires too
wide will cause poorer handling. Either way they will wear faster
than normal, given correct inflation (too narrow at tread edges, too
wide at tread center).
--
Andrew Grebneff
Dunedin
New Zealand
<andrew.grebneff@stonebow.otago.ac.nz>
Seashell, Macintosh, VW/Toyota van nut