I’ve been told by a long-time Pierce-Arrow owner and mechanic that one should use Rotellat engine oil rather than a modern oil in our old cars. I’d sure like other people’s opinions as to whether this is true, and if so, why.
Thanks.
Shell Rotella oil is a very good oil for our Pierce-Arrow cars, as is Castrol GTX.
In addition, so is any good grade diesel engine oil.
I am sure that other members will also chime in on this matter.
Shell Rotella oil is a diesel engine oil. The reason it is recommended for our older cars is because it has higher levels of zinc as do many other diesel oils. The levels are higher than in modern auto oils. Higher zinc levels are desirable for flat tappet engines and help prevent cam wear.
Higher zinc levels were needed in the 60’s when manufacturers went to greater valve spring pressure. I think the jury is out as to if we need the extra zinc for our older cars because of the relative low spring pressures in our older engines. The older oil formulations did not have the levels of zinc that we are talking about here but then engines did not last like they do now.
Cal
In the past I’ve used 10W-30 synthetics and conventional Havoline 30 wt, and always added ZDDP Plus. Hopefully that has covered my zinc requirements. I don’t drive long distances with my Pierce, so I never add oil between changes and really wonder whether I need a 15W-40 like the Rotella T that I found at Walmart. Are there any significant disadvantages with the Rotella T for our cars? Thanks, your comments are always helpful.
As Calvin pointed out,the cars that MAY have problems with low ZDDP are not our Pierce-Arrow cars, but 60s cars with high pressure valve springs and flat tappets. We have lovely, well engineered roller lifters, not push rods, etc. Also, as Calvin pointed out, the jury is out on how much damage the new oils will do to the 60s cars.
You should be fine with whatever top quality oil you put in your top quality car (Pierce-Arrow), and if you are at all concerned, go with the Shell Rotella Diesel, as the specs for diesel engines (oil burners) is much more stringent than for gas burners. There is no need for additives and the big advantage of using Shell Rotella is that you don’t have to worry about whether you using the correct oil.