Origin of the model names

[Gergely Szentmartony 25603]

I am sorry for the silly question but I cannot find the answer anywhere: what is the origin of the model names e.g. Series 75?
In other words: what does the "75" mean in Series 75....and 60, 61, 62, etc. 

[Don Boshara #594]

As I recall, in the 30s or maybe even earlier, GM series and body style numbers for the divisions started: 1 for Chevy, 2 - Pontiac, 3 - Olds, 4 - Buick, 5 - LaSalle and 6 Cadillac. The 75 was not an A, B or C body, which more or less denoted the price level of the body, but generally a Cadillac exclusive.

[Gergely Szentmartony 25603]

Thank you for the answer.
In this case the change was in 1936 because that was the first time Series 36-60 appeared (as far as I know).
However, it is still not clear where Series 10, 20, 30 was coming from in 1934, 1935, and 36-80, 36-85, 36-90 until 40-90 from '36 to '40.
Not to mention Series 70 Eldorado Brougham in '57, '58, but OK, that was another exemption.
It is strange that there's no article or book about clarification of Cadillac model names' origin (at least I do not know about that).

[Bob Hoffmann CLC#96]

That's a good question. I never thought about it, but most of the time the higher the #, the more expensive the car. I'll be interested in what response you get. Bob

[veesixteen]

I think we're all off on the wrong track.  Cadillac started early (1903) giving letters (first) then "Type" and "Series" numbers to identify each group of models. The early cars were Models A, B, C, E, F, K, L, M, S and T (single cyl. engine), D, G, H, L (4-cyl. engine which became the Cadillac "Thirty" in 1909. Then came the Type 51, 53, 55, 57, 59, 61 and V63 (with V8 engine, from 1915-1925). The "Series" numbers started in 1926-27 (like, 303, 328, 314, 355, 370, 452); these numbers designated the engine displacement in cubic inches.

I don't believe there was any rationale for the choice of the subsequent "Series" numbers (in the range from 10 up to 90).  It does appear, however, that the higher the series number, the more luxurious and expensive the model range (exceptions omitted). The "75" designation has been in use for Cadillac's luxury line from the late twenties, it was tagged onto the end of the body style number ("4175" was a Madame X V-16 limousine for with jumpseats).  The series "90" designated the exclusive V-16 cars from 1938-1940.

There is a whole chapter of the Cadillac Databese (which unfortunately is still down) that relates to the Fisher and Fleetwood systems of styling codes.  It does not purport to explain WHY certain numbers or combinatuions of letters and numbers were used to identify specific models , but it does list HUNDREDS of letters and numbers ... for the curious !

[Gergely Szentmartony 25603]

Thank you for the answer.
The beginning of the story is clear. A,B,C, etc., then it became "Thirty" because of the changes in 1909.
51, 53, 55 etc. is also clear.
Then numbering system showing engine displacement in cui is also clear and logical.
Then it became a bit chaotic with the Fisher/Fleetwood body/style numbers from 1934 up to 1943 (M-24). Even here: http://motorera.com/cadillac/cad1930/CAD35S.HTM it can be read: "Some confusion exists regarding style numbers on the 1934-35 Fleetwood bodies."
OK, I accept that I call it "chaotic" only because I did not read the chapter of the Cadillac Database you are referring to. I promise, I will when it is up and running again. I am really curious about that.
In 1946 suddenly the "numbering" system became simple again. Cadillac leaders chose four model numbers (Sixty-One, Sixty-Two, Fleetwood Sixty Special, Fleetwood Seventy-Five) out of the 1."Series 42-60 Special Fleetwood", 2."Series 42-61", 3. "Series 42-62, 4."Series 42-63" 5. "Series 42-67" 6."Series 42-75" previously used and discontinued in 1942.
My original question was related to this era. Where did 61, 62, 60 Special and 75 come from? This numbering system was so "long-keeping" that it was used up to the '90s (75 until '87 and 60 Special until '93).
However, I understand now: I have to read the Fisher/Fleetwood stlying code chapter of the Cadillac Database in order to get clear picture about the origin of the four numbers used after WWII.
Thank you for your help again.