Caddy wheel size question

What year did Cadillac go from 16" to 15" wheels?
Paul

 

I think 1939-46 use both 15" or 16" wheels. 15" on the "small series" (Series 50, 52, 60S, 61, 62). Large Series (Series 38, 39, 40) used 16" wheels. 1947-up is 15" only

 

Cadillac he****s(series 86) had 16" wheels intill at least 1949. If that wasn't the last year it was close to the end of them using 16' wheels. I believe that limousines(series 75) used 15" wheels, but I'm not sure.