I am not sure as to what extent lawsuits came into play. Sinclair was one of the largest industrial companies of the twentieth century, with lubricants for every potential use, one of the broadest lines to be found. Sinclair Pennsylvania Mobiline was a relatively new product in the late 1920s, although I've never seen a firm date as to exactly when it was introduced (see note below). Pennsylvania grade crude oils were considered to make the best lubricants, and any "Pennsylvania" oil was considered a premium product. Sinclair, largely a mid-continent refiner, had used crude oil from Kansas, Oklahoma, Texas, and other mid-continent oil fields. Somewhere I've seen it suggested that Mobiline was introduced in 1928, as Sinclair's first Penn grade oil. At the time Vacuum Oil was primarily a lubricants manufacturer, and had used the trademark Mobiloil in the U.S. since the early years of the century. In the time period between 1926 and the 1931 merger with Socony, Vacuum was in expansion mode. They were expanding their "Mobil" prefix to other products, Mobilgas in 1929, Mobilgrease, etc. As I've heard, in expanding their use of the Mobil prefix, they purchased from Sinclair any claim to use of the Mobiline trademark, under threat of legal action that neither could afford. It is my understanding the Sinclair Pennsylvania Mobilene became simply Sinclair Pennsylvania in early 1931. I'll see what we can confirm about this interaction between the two companies.
Last edited by Carolinatraveler; Tue Apr 11 2017 06:32 PM.