What oil to use with the additive I don�t think is a question that has a definitive answer. Most quality oils are similar enough that there are not great differences in the oils. I�ll share what I have learned, especially over the last years. By going into any auto supply store you can see, by the fact that there are many different brands and types of oils, that there isn�t one answer.
Synthetic, blend, or dinosaur juice? It seems that the quality of all major brand lubricants may well exceed anything most enthusiasts may need. Synthetics are the best; many people, including some manufacturers, will admit that conventional oils are adequate in most appli-cations.
If your car�s owner�s manual recommends a single weight oil and/or non-detergent, what should you do? Great improvements in oil since your car was manufactured make those old recommendations no longer valid. One excep-tion: If you have been running a non-detergent oil it might be advisable to stay with what you have been using until a new engine is built.
Engine manufacturers realized in the early 1970�s that the new multi-grade oils were superior and completely dropped recom-mending single grade oils. I recommend using the grade of oil recommended during the last production dates of your engine type if it includes a multi-grade. Lighter weight oils get more horsepower to the wheels and if properly used can increase engine life. The rule we use is that the oil pressure should be 10 Psi for each 1,000 Rpm of redline. i.e.: If the redline of your engine is 6,000 Rpm you should have 60 Psi, 50 Psi with a redline of 5,000, etc. If these numbers cannot be reached using a 20W-50 it probably is time for a new set of bearings.
If anything changes in the future I�ll put out new data. Now with the new additives and some new oils we have products that will keep our engines purring like they were designed to do! Just remember to have ZD-DP at or above 1,600 ppm for flat tappet engines!
Keith M. Ansell
Foreign Parts Positively, Inc.
19900 NE 189th Street
Brush Prairie, Washington 98606