I think you probably meant steam engine fuel oil, and yes they did.

There were a whole series of watering and fuel oil stations all along the SP lines. I even believe there even were several mainline fueling stations and water, at places like SLO, Indio, and Yuma, for fueling and topping off through trains. And for years you could still see the remnants of that in Indio, near where the depot stood. I also believe that this was the case in Yuma, as well.

Although in those days, they also changed out a lot of steam power, much more often, depending on speed requirements, type of service (passenger or freight ), and the ruling gradient, with newly fueled and watered power from the vast network of roundhouses, that also served almost every terminal, big and small.