If this is joke..okey, but otherwise..no sense!

Since tires are constructed for specific duties a car tire is not designed or engineered to be used as a motorcycle tire. Car tires are designed to hold the road when the weight is applied directly downward.  Therefore the tread pattern is such that the contact patch designed does not include the sidewall. Since motorcycle tires work more on an axis they are designed with the contact patch on the bottom and sides to have consistant contact with the road. ONce you get over on a car tire your not only loosing that contact tread you are also appling force to a part of the tire where it was not designed to handle.  That being said, tires are basically over engineered to probably withstand those pressures (for a while).  I would open the wallet get a good pair of Metzlers or other good motorcycle tire and ride on without the nagging thought of a failure.