RE: [A/S] new tires Radials DO Have LOWER rolling resistance

["Oliver Filippi" <ofilippi@xxxxxxxxxxxx>]

Charles,

I respectfully disagree with your conclusion on bias ply tires having less
rolling resistance than "squashed" radials.

When Michelin first introduced their radial tires to the American market,
(in the late 1960s) they did it with truck tires (did not bring in any
automobile tires).

Michelin actually loaned their radials to truck fleets and had them verify
the improved fuel economy of the radial tire on the truckers' normal routes.
The savings were readily measurable!  This savings was more than enough to
pay for the then more expensive radial tires even at the low fuel costs of
the late 1960s and early 1970s.

Radials roll with significantly less resistance.  This is due to radial
construction, which COMBINES a very flexible sidewall and a stiff belt.
Thus there is far less internal friction and "squirm" absorbing energy in a
radial vs. a bias design.  The secret to the radial is the flexible radially
run plies combined with the stable belt.[Hence the squished look, which may
not look neat, but if it works, so what?]

You may recall in the early 1970s, American tire makers tried to combine the
rigid belt with the conventional bias ply carcass, with disastrous results -
the tires self destructed since the squirming bias plies literally sheared
and separated themselves from the belt.

Likewise, with  virtually no squirm, given the same rubber compound and
tread pattern, a radial will have superior traction on wet pavement, since
the rolling footprint is not squirming and breaking the traction between the
tired and the road surface.

Oliver Filippi