Gasoline Automobiles, First Ed‪.‬

This 1921 book presents the "essential principles of automobile construction and operation" and provides basic troubleshooting advice for drivers who run into problems. In the 1920s, companies began making multiple different versions of their cars so that there would be an option for every economic bracket. However, it wasn't until the 1930s that certain parts that frequently broke became standardized within the company. Thus, if a car part broke, it was difficult and expensive to find a replacement part.