Importance Color Theory in Web Design The old saying “where the rubber meets the road” usually means something is reach ing a critical point. Naturally the expression refers to automobile tires, since those crucial pieces of rubber are the only part of your car or truck that are supposed to make constant contact with the pavement. That’s why it’s important to know and maintain the correct amount of air pressure in vehicle’s tires. To get the right amount, turn not to the tire itself but to the vehicle and a label will often be located in the doorjamb. That’s where you can find the vehicle manufacturers suggested inflation level for car or truck. If it’s not there, check the owner’s manual. Recently, a reader asked why tire sidewalls often show a pressure rating, shown in maximum pounds per square inch (psi ) that differs from the vehicle maker’s recommendation. This may be obvious...