On Mar 9, 10:45*am, Brian Bange wrote:

...It has P165/80R13 tires on 4 lug wheels...

The nominal OD of that tire size (independent of "dynamic" effects)
is:

165*0.8*2+13*25.4 = 594mm.

Brian, you probably already know this, but for everyone else the parts
of a tire size like "165/80R13" a

165 - Width in millimeters
80 - Aspect ratio; ratio of height to width
R - Type and/or speed rating. R=radial
13 - Wheel size, same as the tire ID in inches (yes, inches)

Nominal OD = (width*aspect)+(wheel size*25.4)

Thanks, Bob K.