Oil is Killing our Cars

March 15 , 2008

In November 2006, I published the first of the “Oil is Killing Our Cars” articles and virtually all major engine builders and camshaft manufacturers are now admitting that we were right in condemning the new oils. These oils were causing at least 75% of cam failures (American Engine Rebuilder’s Association, pg. 8, Jan-Mar 2008)!! Now with everyone admitting the problem, solutions are surfacing.

"If you're currently putting mileage on your classic vehicle and using the latest API grade SM oil, you are almost certainly doing irreversible damage to your engine."

What’s this all about? In the middle 1970’s catalytic converters (cats) became mandatory on most cars. By the middle of the 1980’s it was noted that cats had a limited lifetime. With the addition of computer controlled fuel delivery, oxygen sensors were introduced into the exhaust system. Soon after this it was noted that one of the Extreme Pressure (EP) components of oil, ZDDP (Zink-Dialkyl-Dithio-Phosphate), caused deterioration of the oxygen sensors and cats. The auto manufacturers started to redesign engines so that they didn’t need much of this additive and by 2005 all major oil manufacturers started to reduce ZDDP in their oils with the goal of meeting at least “SM”, GF-4 classification. Most engines designed before 1980 were with flat tappet construction and were designed around and had to have ZDDP. As these “old” engines today use only a small percentage of the total lubrication oil consumed, the removal of ZDDP did not affect the majority of the oil market. Of the 500 million registered cars in the U.S. only 10 million are older than 1988 (2%). Most well known companies therefore choose not to help people who own older cars, especially those with flat tappets. Those that are acknowledging our needs are limiting what is available and even what they offer may not be sufficient. The bottom line here is that if you are not using a lubricating oil with at least the necessary amount of ZDDP your car was designed to use (flat tappet design or high performance hot rod) you are damaging your engine.

Here’s the number we need: Around 1,600 Ppm. with 2,000 ppm being about the highest concentration of ZDDP (Zink-Dialkyl-Dithio-Phosphate), a minimum of around 1,300 ppm. Most of today’s oils have reduced this chemical to near 650 (400 to 800) ppm and in most cases it seems their goal is to reduce it further! Another point: Zinc and/or Phosphate do not equate to protecting our engines. ZDDP is the compound that protects our engines. Don’t accept oils or additives that claim to have what we need if they give just zinc and/or phosphate numbers.
Differing ZDDP compounds have different temperature tolerance, read the manufacturer’s literature!

There seem to be only two major North American oil companies currently producing products for us and they are Castrol (Syntec 20W-50 in the black bottle with “Recommended for Classic Cars” on the back) and Valvoline (VR-1 20W-50). Joe Gibbs Racing Oil is now producing street oils that seem good for our engines and distribution of this product is just starting in North America. Red Line Oil, a smaller manufacturer on the West Coast, is available at many racing shops, with 10W-40. Eastern States seem to be able to find Brad Penn Oil, Swepco and Hi-Z. Penrite Oil in Australia. Other small companies are starting to notice our problem and are bringing out new products.

Now comes The News! Two companies are now producing ZDDP additives that can be added to any oil! Rather than try to find oils that protect our cars, you can now add a prescribed amount of one of these additives to your oil of choice. The more concentrated the additive the better. Be aware that the larger the dose of additive required to reach 1,600 ppm, the “carrier” in the additive will probably dilute your oil and reduce the oil’s designed lubrication abilities.

First to come to market was a product called “ZddPlus”. Kirban Performance, the manufacturer, has a web site www.ZddPlus.com that expands on what we have been learning over the last year and their approach to solving our problem. They are seemingly careful not to suggest any brand of oil and claim their product should be compatible with any company’s products. There is no new information on this web site but it answers many questions. They market directly on-line or through dealers.

The second product is “Cam-Shield”. A person that has been in the lubrication business for many years has developed this product and is a very experienced lubrication formulator for some of the largest racing programs from road racing to off-road. This product is very concentrated so it does not dilute your base oil. It comes in a bottle that has a built-in measuring device so that you can accurately dispense the product based on how much oil you put in. This company markets through local dealers and on-line www.Cam-Shield.com. This company also does not suggest any single brand of oil.

Other products that contain ZDDP are EOS, Torco, Crane, CompCam and STP. These are not specifically formulated for our cars and have limited use. Some are specifically to be used only during break-in. There may be others.

So we have a final answer! We can now know, by adding the ZDDP that was mandated out of most oil, that we are not internally wearing away our engines at an accelerated rate by restoring the ZDDP that our engines were designed around.

I want to acknowledge and thank the companies, large and small, and the individual people who have written and called me with input on this subject from all over the world. Many were aware of this problem even before my first article was published. All these inputs are used and are appreciated.

What oils are best for our cars?

What oil to use with the additive I don’t think is a question that has a definitive answer. Most oils are similar enough that there aren’t great differences in the oils manufactured by quality companies. 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 would ever need. Synthetics are the best; many people, including some manufacturers, will admit that conventional oils are adequate in most applications. One manufacturer admitted to me that all their products were similar, just marketing and some modifications to additives got higher prices and sold more products.

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 exception: 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 recommending single grade oils. I recommend using the grade of oil recommended during the last production dates of your engine 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 ZDDP at or above 1,300 ppm for flat tappet engines!