Quality Is Not as Simple as It Seems 

Quality control is the term with which we are most familiar. As the term is used by industry, it involves testing of units and determining if they are within the specifications for the final product. There are aspects of QC that go beyond testing or represent a different way of testing. For most of us, quality inspection is what we think of when someone says QC. Quality inspection involves the actual laboratory testing of finished oils. We look at viscosity, volatility, metals content, flash point, pour point and various other properties of the oil to make sure that what we ship is as advertised. It’s important that
the inspection tools used are operating properly and that the test procedures are current. Test precision—repeatability and reproducibility—must be maintained.

How do you know that the components are right? That’s what some might call quality conformance. Most labs test incoming raw materials. Do they know what controls are used by their suppliers to assure that what they ship is correct? Do they know if the supplier has made its own quality assurance checks to know that what is being shipped is on-spec?

When I was at Pennzoil, we had a very interesting quality issue that developed. A new additive source began shipping engine oil additive from the Gulf Coast to our West Coast plant in the Los Angeles area. The supplier’s specification called for a viscosity of 115 centistokes at 100 degrees Celsius. The first tank car or two arrived right on the mark. However, the third car arrived with a viscosity of 150 cSt. It was barely out of spec (the maximum allowed was 145 cSt, as I remember) and raised a yellow warning flag. Because of demand and the fact that everything else was correct, we accepted it but required the supplier to make corrections to the blend to fix the problem.

Things went from bad to worse over the next two shipments and caused us to put a hold on further receipts. After intense efforts by both Pennzoil and the supplier, we figured out what was going on. When an automotive engine oil additive is manufactured, the hottest, most viscous additive component, which may be over 150 C, is blended with diluent oil to reduce viscosity and cool the blend. 

Apparently, this component, which is dispersant, was not being cooled enough. When the other components were blended into the mix, a secondary reaction was occurring that increased the viscosity of the additive. The supplier assured us that this reaction didn’t have any impact on the performance of the additive. Nevertheless, normal quality control wouldn’t have caught this had it not been for the lubricant blending plant chemist.

The task of making sure that components received are correct is a joint responsibility of the supplier and the customer. Limits must be set and agreed to by both parties and adhered to without lapses.

Additives are a more complex system, but even the most basic of components has the same rules. Another aspect of ensuring quality is quality protection. 

Again, I was involved in an incident that was the result of poor quality protection practice. We were getting 100 neutral base oil from a supplier. With viscosity of 20 cSt at 40 C, 100N base stock is used in lower-viscosity motor oil and transmission fluids. The supplier was an old source to us, so we were pretty confident of their product quality. However, we began receiving railcars with cloudy oil. The obvious source was water. We checked with the supplier, and they assured us that nothing had changed. 

This continued off and on for a few shipments. We requested that we be allowed to review the operation ourselves. One of our purchasing people and a technical service representative visited the plant. The tank car, which had capacity to carry 23,000 gallons, was rolled up to the loading spot and the central dome was opened up. A fill spout from the main bulk storage of 100N was swung over the car and began to load through the dome. 

Were it not for bad weather, it might have taken a lot longer to figure out the problem, but it started to rain. There was no roof over the fill spot and no tarp or other protective covering placed over the dome, so some rainwater mixed in with the load. It only takes about 20 parts per million of water to cause a haze in oil, which in this case was less than 0.5 gallons. The point of the story is that your suppliers need to protect the quality of their products or there will be problems.

Quality assurance is a way of preventing mistakes and defects in manufactured products and avoiding problems when delivering products or services to customers. Not only are your suppliers obligated to send you on-spec components, but you are expected to send on-spec products and services to your customers. This one is where the rubber meets the road, and of course I have an example of this as well. 

As some of you may know, outboard motor oil has some unique characteristics. Since it is designed to lubricate a water-cooled two-cycle engine, the oil is mixed with fuel at a relatively high ratio of fuel to oil (100:1). These formulations are also usually ashless. Therein lies a potential problem.

Let’s talk about plant operations for a minute. If your plant blends large quantities of motor oils, it is often necessary to flush the fill system to make sure there is no cross-contamination. Normally, these flush oils are stored and worked off in blends at a small percentage. All well and good, except when the flush oil, which contains motor oil additives, comes into contact with an ashless formulation like outboard motor oil. What makes it worse is that often the impact of the contamination is not immediately obvious. 

Back to the outboard motor oil: Complaints started to come in, instigating a recall and compensation to those who were affected. After a thorough process review, it became clear that flush oil was the culprit. Interestingly, other issues surfaced that, although not directly related to the outboard situation, could be a possible source of future problems. Bottom line: Check your systems to make sure potential sources of contamination are eliminated.

Finally, the American Petroleum Institute symbol (donut) and certification marks (shield) are your guarantee that an oil meets all relevant quality standards. Those include the formulation details on the license, the testing to back up performance claims, and the proper labeling standards.  

According to the Engine Oil Licensing and Certification System (API 1509), which is the definitive standard for engine oils manufactured and marketed worldwide, “The API EOLCS is designed to define, certify and monitor engine oil performance that vehicle and engine manufacturers and the oil and additive industries deem necessary for satisfactory equipment life and performance. The system includes a formal license agreement executed by the marketer with API. The program’s marks are intended to help the consumer identify products that have satisfied the requirements for licensing and certification.”

Please note that there is a sample audit system in place to verify that oils with the API marks are routinely and randomly collected. They are then analyzed for conformance to the data registered with their license. 

API 1509 continues: “All engine oils licensed to use the API marks are subject to conformance audits. Conformance is determined by comparing measured physical and chemical properties of the oil with licensing data on file at API. In addition, a limited number of products may be randomly selected for engine and bench testing.”

There is a process for evaluating noncompliant results, and it allows for some “fudge factors.” However, if errors of major significance are detected, there is a process for correcting the error.

Many states do their own enforcement, which may include sampling for viscosity. If the viscosity doesn’t properly reflect the SAE grade on the label, the oil marketer may be ordered to remove all oil from the shelves. That is not a pretty picture and is very costly. Obviously, good record keeping is a must.

This is far from a complete review of quality. Just remember that there is more to quality than inspections. Quality assurance, quality conformance and quality protection are key parts of the equation. So when quality is on your label or in the bulk tank at your fast lube, it needs to meet all of the criteria.   

Steve Swedberg is an industry consultant with over 40 years experience in lubricants, most notably with Pennzoil and Chevron Oronite. He is a longtime member of the American Chemical Society, ASTM International and SAE International, where he was chairman of Technical Committee 1 on automotive engine oils. He can be reached at steveswedberg@cox.net.