The new Series "F" was unveiled which sported a slanting windshield, distinctive only for this series. 1926 was spent strengthening Checker's marketing position and sales organization, so the cars remained the same.

The big news for 1927 was the addition of a 6-cylinder engine, and the cars were now known as the ''G-4'' and the "G-6". They looked like all the big sedans of 1927. The Series "E" model stayed on a little while longer to keep some of the old customers happy. By the end of 1927 there were 18 manufacturers of automobiles. The competition was stiff and the demand for more style for the customer's money was evident. The company had a bad year and a drastic change was needed.

In early 1928 Checker went to the drawing boards again to design a look completely different from anything the country had ever seen in the cab industry. On October 4, 1928 the new series ''K'' rolled off the assembly line. It was a real traffic stopper, and that day was proclaimed as glorious as the big day in 1923 (the day the first Checker rolled off the assembly line in Kalamazoo).

In January the Company acquired control of Checker Cab Sales Corp. in New York. This company handled all the Checker business in and around the New York City area. By the end of January, 1929 there were 21,000 taxis in New York City, and, of this total, over 8,000 were Checkers.