Car Serial Numbers
The following serial numbers are listed to help identify the year and model of your Hupmobile. These numbers are taken from William Cuthbert's book, The Hupmobile Story, From Beginning to End, 2004, page 175. Corrections to these numbers are made as they are identified by Club members. Few factory records exist that identify models by serial numbers expecially during the period of 1939 to 1940 when the company renumbered 1940 Skylarks to sell them as 1941's.
| Year | Model | Car Serial Number Range |
| 1909 | 20 | 1-500 |
| 1910 | 20 | 501-5000 |
| 1911 | 20 | 5001-12000 |
| 1912 | 20 | 12001-14500 |
| 32H | 25001-28902 | |
| 1913 | 20 | 14501-15780 |
| 32H | 28903-40000 | |
| 1914 | 32H | 40001-52000 |
| 1915 | K | 52001-60000 |
| N | 60001-65443 | |
| 1916 | N | 65444-77498 |
| 1917 | N | 77499-87514 |
| 1918 | R-1 | R-1 - R-15000 |
| 1919 | R-2 | R-15001 - R-20000 |
| 1920 | R-3 | R-20001 - R-30000 |
| R-4 | R-30001 - R-40000 | |
| 1921 | R-5 | R-40001 - R-55000 |
| 1922 | R-6 | R-55001 - R-60000 |
| R-7 | R-60001 - R-65000 | |
| R-8 | R-65001 - R-75000 | |
| R-9 | R-75001 - R-90000 | |
| 1923 | R-10 | R-90001 - R-100000 |
| R-11 | R-100001 - R-120000 | |
| R-12 | R-120001 - R-140000 | |
| 1924 | R-13 | R-140001 - R-160397 |
| 1925 | R-14 | R-160398 - R-175397 |
| R-15 | R-175398 - R-179396 | |
| E | E-1 - E-9300 | |
| 1926 | A | A-5001 - A-38800 |
| E1 | E-9301 - E-15000 | |
| E2 | E-15001 - E-20550 | |
| 1927 | A | A-38801 - A-69700 |
| E2 | E-20551 - E-25000 | |
| E3 | E-25001 - E-29150 | |
| 1928 | A | A-69701 - A-115000 |
| E4 | E-29151 - E-32500 | |
| M | M-5001 - M-13500 | |
| 1929 | A | A-115001 - A-155000 |
| M | M-13501 - M-27200 | |
| 1930 | S | S-5001 - S-30200 |
| C | C-5001 - C-9999 | |
| H | H-5001 - H-5999 | |
| U | U-5001 - U-5099 | |
| 1931 | 137U | U-5100 - U-5574 |
| 125H | H-6000 - H-8099 | |
| 121C | C-10000 - C-14499 | |
| 118L | L-50010 - L-11999 | |
| 114S | S-30201 - S-44499 | |
| 1932 | 216B | B-5000 - B-8499 |
| 222F | F-5000 - F-8754 | |
| 226I | I-5000 - I-5712 | |
| 237U | U-5575 - U-5706 | |
| 225H | H-8100 - H-8545 | |
| 221C | C-14500 - C-15174 | |
| 218L | L-12000 - L-13093 | |
| 214S | S-44500 - S-46709 | |
| 1933 | 326I | I-5751 - I-6000 |
| 322F | F-8801 - F-9500 | |
| 321K | K-5001 - K-9600 | |
| 321KK | KK-9001 - KK-9300 | |
| 316B | B-8500 - B-9962 | |
| 1934 | 427T | T-5001 - T-5788 |
| 421J | J-12001 - J-13868 | |
| 426I | I-6001 - I-6553 | |
| 422F | F-9501 - F-10165 | |
| 421K | K-9601 - K-11109 | |
| 421KK | KK-9301 - KK-9600 | |
| 417W | W-5001 - W-8000 | |
| 1935 | 517S/W | W-8001 - W-10586 |
| 518D | D-5001 - D-10900 | |
| 521J | J-14001 - J-14933 | |
| 521O | O-5001 - O-5400 | |
| T | T-6001 - T-6902 | |
| 618D | D-10901 - D-11773 | |
| 618G | G-5001 - G-6749 | |
| 621N | N-5001 - N-5289 | |
| 621O | O-5401 - O-5475 | |
| 1937 | No Production, Factory Closed | |
| 1938 | 822E | E-35001 - E-35300 |
| 825H | H-25001 - H-25197 | |
| 1939 | 915R | R-100501 - R-100531 |
| 922E | E-72001 - E-72800 | |
| 925H | H-30001 - H-30200 | |
| 1940 | 015R | R-100501 - R-100926* |
Notes:
The body and engine numbers were not matched while the engine and transmission numbers did.
The motor numbers and the transmission numbers are stamped into the castings.
A group of 1940 cars were re-numbered and sold as 1941 models.