<VV> Tire size vs air pressure survey

[Jim Davis]

It is the air pressures in the tire hat holds the car up.  The more 
pressure the more load the tire can carry.  It is hard for me to 
consider the suggested pressures found on the glove compartment door of 
my 1965 Corsa revelent with today's tires.  After all, the original 
equipment tires were Firestone 2 ply nylon, bias ply in the 6.50x13 
size.  Since the early 1970s the tires have been 195/70-14 on five spoke 
Fenton 14x6 wheels.  The current tires are Kumho Solus KR21s with a 2 
ply polyester with dual steel belts.  The Corsa has the F41 option with 
quick steering box and arms and Positraction.   A little white shoe 
polish and an empty parking lot show that 24 psi front and 36 rear is 
the best compromise between ride quality and handling.  This is a trip 
car with over 300,000+ miles on it (one owner).  Weighing the car shows 
1,100 lbs on the front and 1,700 on the rear.  Max recommended tire load 
is 1,356 @ 44 psi.   Thus the minimum air pressure would be 18 psi on 
the front and 28 on the rear.  Any extra loading to the car besides the 
one driver whose weight is included would have to be compensated for.
Jim Davis


On 12/31/2013 11:34 AM, Paul Fox wrote:
> Of course you are correct provided you use what the car came with from the factory. But if you make any changes which most of us do. I would make sure you talk to the experts to see which if any changes need to be made in pressure. Like I say there are many variables.
> Sorry didn't mean to start a flame war.
> Paul Fox
>
>
>
> On Tuesday, December 31, 2013 11:12 AM, gerg <gergwerks at comcast.net> wrote:
>    
> I just had new 185/80s put on last night. I expect the tire shop put 32lbs in all. I'll check. However, I did notice that the outer edges of the front tires showed no road contact - no dirt / white dust on the outer edges, center contact only. Rode a little stiff up front too. I'll check them and drop front pressure and see what happens.
>
> Thanks,
>
> Greg Blakeney