In 1929, DAT built a small-car prototype called the DAT 91. They ended up marketing this model as the DATSON Type 10 ("son of DAT"), since it was a shrunken version of the earlier 31. "DAT" was now a backronym for Durable, Attractive, and Trustworthy. The car fit into a new category of small cars, limited to half a liter's displacement. The production version was powered by DAT's own four-cylinder, side-valve engine of 495 cc. It (and the inauspicious "DATSON" name, with "son" being close to 損, the Japanese word for "loss") was replaced by the Datsun Type 11 in 1932.