RE: tyre pressure

[SOP8920@Siena.edu]

paul:                                                                       
> I have heard that for driving on sand, you should reduce tyre pressures       
> to get more of the tyre in contact with the sand.  Does the same thing        
> apply to snow driving?                                                        

>NO!                                                                             
>when driving in sand, the object is to float on the sand.                       
>otherwise, your belly be dragging and your wheels be hanging.                   
>hence, low tyre pressures, so they don't cut in and sink.                       
>when driving in snow, the object is to get the tires on the pavement.           
>in this case, low pressure = no traction                                        
>frank                                                                           


Right... that is why, for winter time many people switch their performance
rubber for snows of a smaller width. 205s to 195s say. Except, It's often
suggested that running on a lower inflation pressure will aid traction in the
snow as well. I believe the logic is that decreased inflation pressure 
will increase the length  of the contact patch, while keeping  
the width of the contact patch the same.

I'mnot sure if I agree with you on this point. You definately don't want float
in the sand... but I don't think decreased tire pressure in the snow will
inhibit the tire's ability to "cut in and sink". Hmm... food for thought I
guess. ;) If I had to wadger, which I will this winter... I would probably run
at normal tire pressure if I had snows, or if I had all seasons, I would run at
a few Psi less than during the summer. Any tire experts? 
                              

			 -Osman Parvez
                                89 200q
                                Siena College
                                Albany NY