In the Department of For What It's Worth, I suspect the B&SR tank cars carried more gasoline than fuel oil. After all, in pre-World War II America, most people heated their homes with coal, especially in more rural areas where gas lines did not run, and the refiners and wholesalers had not yet developed the fleets of trucks to deliver gasoline to service stations and dealers. But most people also had a car, which required gasoline. Down here in Pennsylvania, the Susquehanna River & Western, a narrow gauge line northwest of Harrisburg, had two tank cars, just like the B&SR. I am told that the two cars carried the same amount of gasoline as the standard gauge car that brought it to the interchange point.