Although the Model L Cadillac Limousine had a planetary transmission and 5" x 5" bore and stroke like the single cylinder Cadillac Runabout, the two models were entirely opposite in concept. The single cylinder was a horseless carriage for the masses, the Model L a Nabob's throne-on-wheels. Whether due to the Alanson Brush patent squabble, acute marketing perception, or both; Cadillac came up with a four cylinder design which met the expectations of customers who wanted just a bit more than the best one cylinder car could offer -- an inexpensive. easily maintained, long lasting, precision built car -- a "single cylinder Cadillac with four cylinders" - the Model G. Serial numbers on plate on rear of body or on dash (with engine number). Engine numbers were stamped on top surface of crankcase - in front of and to the left of number one (front) cylinder. Model G engine numbers: 30003-30425 (1907), 30426-30500 (1907-1908).
   CADILLAC - MODEL G - FOUR: Same as 1907 Model G except: Limousine added to the line; One or two passenger rumble seats available, of different pattern than the single rumble of 1907. Note: There were no changes in the Model G engine for 1908, but the advertised horsepower rating was increased from 20 to 25. This was due to the newly instituted ALAM horsepower formula, which gave the Model G a horsepower rating of 25.6. Cadillac had always been conservative in horsepower ratings. The ALAM rating was also conservative, and gave the same rating to every engine with the same bore and number of cylinders. There was no allowance for design, accuracy or precision of manufacture, superior practice in fits and tolerances, etc.. Cadillac, although having had a voice in establishing the ALAM formula, soon took exception to being rated the same as the least sophisticated manufacturer. Although engines were tested for actual developed horsepower, it was to be many years before horsepower curves were publicized.
   Model G: Introduced November, 1907. Calendar year sales and production: 1030 (1907-1908). Model year sales and production: same. The President of Cadillac was C. A. Black.
   Note: The bulky, complicated, planetary transmission luxury fours were too great a first leap from the single cylinder, which had become passe. The compromise Model G design formed a solid basis for the "Thirty," which was to be the single line for Cadillac through 1914. Had Brush design concepts been perpetuated, the company might well have failed. Its move into a firm position in the luxury car field was to wait another seven years.
More ...