Reply To: Today's Motor Oils
John & Shirley Harvey
As a general rule, any detergent motor oil sold today is far superior to anything sold in 1954. I would find it unlikely that your car has not been using what ever was current in motor oils, simply because the “currrent” oils were what were going to be available. I’ll have to dig back in my memory banks, but it seems to me that if you get an oil that has the rating on the cap of SJ or lower letter, like SH, you even get some of the zinc. I think I recall that SM is the one with the reduced zinc content. In truth, if you are not driving 20,000 miles a year, pulling a trailer or drag racing, SM is not likely to damage your engine.