I generally change my oil pretty regularly, but last time I went a little too long and my oil volume was low. Pressure always looked good.
buy 10-40 grade fully synthetic .you cant go wrong .STP?scientifically treated petroleum .the first form of synthetic oils
it wont help anything the best thing you can do is change the oil often . you start putting 'super slickum' additives in an old motor all it will do is make it leak more
