Oil is Killing our Cars, Continued…

If you’re currently putting mileage on your classic vehicle and using the late-st API grade SM oil, you are almost certainly doing irreversible damage to your engine.

– William C. Anderson
‘New Oils and Old Cars’
Old Cars Weekly 48

In November 2006, I published the first of the “Oil is Killing Our Cars” articles and virtually all major engine builders and camshaft manu-facturers 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.

What is this all about? In the middle 1970’s cat-alytic 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 ex-haust system. Soon after this it was noted that one of the Extreme Pressure ( EP ) components of oil, ZDDP ( Zink-Dialkyl-Dithio-Phos-phate ), caused deterioration of the oxygen sensors and cats. The auto manufacturers started to re-design engines so that they didn’t need much of this additive and by 2005 all major oil manu-facturers 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 “Recom-mended for Classic Cars” on the back ) and Valvoline ( VR-1 20W-50 ), both are about 1200 ppm or just at the minimum ZDDP. 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 ( 1600 ppm ).

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 might protect our cars, you can now add a pre-scribed amount of ZDDP 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 dilute your oil and reduce the oil’s designed lubrication abilities.

First to come to market was a product called “ZddPlus”. Kirban Performance, the manu-facturer, has a web site www.ZddPlus.comthat 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 website but it answers many questions. They market directly on-line or through dealers. It comes in a 4 ounce bottle that is recommended to be added to 4 or 5 quarts of oil.

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 concen-trated 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 and what you need to add. This company markets through lo-cal dealers and on-line www.Cam-Shield.com. This company also does not suggest any single brand of oil. It comes in either 4 or 8 ounce bottles with a measuring device.

Of these two additives, “Cam-Shield” is the most concentrated, has two types of ZDDP for complete coverage, comes in a bottle that makes it easy to administer the correct dosage and is lower in cost per treatment.

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 comp-anies, 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.


Keith M. Ansell
Foreign Parts Positively, Inc.

19900 NE 189th Street,
Brush Prairie, Washington 98606