I have a 1948 Super A that has always run on non-detergent oil. I had a hard time locating some as Tractor Supply no longer carries it. I stopped at an Ace hardware store and picked up five quarts of their house brand.. But it is called lubricating oil and not motor oil and is a Mineral oil with additives for low impact use. Is this considered ok to use in a tractor? I thought that it may be for air compressors. I also may be changing the oil and filter more than needed(yearly) as I run it about 15 hours per season. Can I go two years between changes? I don't wish to change to detergent as I am afraid of creating another problem with possible engine issues.