A 225 75 R16.5 tire is the standard replacement.
165/80r15
Yes, that is reasonable.
A spare, A doughnut, Une roue de secours
The ideal replacement is the same size it was built with.
165/80x15
165/r15
165 r 15
165/-15
Per square inch
165/80 r15
165/75/13
A 225/70R14 if remember correctly. Good luck