IF your engine's got a filter, which isn't a certainty, it will be a canister mounted on the intake manifold with a couple of brackets resembling muffler clamps. Not all engines came equipped with a filter, it was an extra-cost option.
Non-detergent oil has NO application in automotive-type engines, and hasn't for a long time. Use a straight-weight HD oil if you choose, or one of the heavier multiweight oils like 20W50. You'll have no problems using HD 30 oil in the summer, and 20W in the winter, but 20W50 will work year-round without any trouble.
Jerry
