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Time was, researching a term paper or a theme meant going to the library to look up information. In fact, most of us went to the library as a socially acceptable place to hang out and be with our friends. The Encyclopedia Britannica and the Readers Guide to Periodic Literature were the main-stays of our literature searches. As a chemistry major, I also frequented Chemical Abstracts.

Today, all of that and much more is at the fingertips of anyone who can get to a computer and type in the word Google or Yahoo. Yes, the internet is a goldmine of information. Some have said that the amount of information available doubles every year or two. With the internet, the rate must be going through the roof. (Go to Google and search on your name or telephone number. The results may astound you!)

There is one big caveat to the internet: The information available is, in many cases, unreviewed and frankly, not true. For an education on what has become known as Urban Legends, go to Again, youll be astounded at what you thought was true – or should be true – versus what the researched facts show.

By now, Im sure that many of you reading this are saying to yourselves, What in Heavens name does this have to do with automotive engine oil?

Well, as a basic fact, most original equipment manufacturers will tell you that very few automobile owners read their owners manual. Maybe its a guy thing or maybe it is because we think we know what to do. My wife reads the maintenance schedule and wants to follow it to the letter. Shes probably right to do so, but Im from the old school which says that it isnt necessary to do all those things, and besides, I know what Im doing!

Recently, I got on the GM website (I own a GMC pickup) and found a place where I could register my truck, select a local dealer and get service bulletins and other safety-related notices e-mailed to me. The website also has an online owners manual for my truck – a really good idea.

Likewise, the internet has a large number of websites devoted to engine oil. There are also many postings about viscosity, friction, base oil and additives. Many of these are academically oriented, e.g. research papers by senior and graduate students as a part of their course requirements. Many are from oil marketers, both large and small.

Then there are the others. Many of these sites are selling oil and tend to cast their recommendations to fit the products they are promoting. There is nothing wrong with that – as long as the facts are in line with industry knowledge. Unfortunately, some sites have got it really wrong. The main areas of confusion are related to viscosity, drain intervals, oil quality and chemistry. Without singling out anyparticular website, lets take a tour of some of the specific misinformation that is being promoted.

A Million Hits

Many of the websites are dated. Thats not surprising considering that once its out there, it stays there, unless someone pulls it off. This results in some information about API categories that doesnt reflect current requirements. (By the way, a search on Yahoo retrieves over a million engine oil sites and over 500,000 viscosity sites). Im not recommending that anyone police these sites, but Question & Answer or FAQ sites are a real minefield of conflicting recommendations and understanding.

I also rummaged around a number of major oil marketers sites. Most are pretty well up to date on standards, designation and the basic science of engine oils, although a couple still havent remembered to update their data sheets and bulletins to reflect the roll-out of ILSAC GF-4/API SM.

But what about sites beyond the majors or the OEMs? Read on.


Viscosity is the internal resistance or friction between layers of a fluid. Most often it is referred to as resistance to flow. Most websites have that right. Some think that the higher the viscosity the better, without regard to pumping, cranking or any other property of the oil.

The SAE viscosity classification system as documented in SAE J300 takes a beating on the designations. Some sites insist that all grades must be W, while others understand correctly that W is reserved for lower-temperature viscosity measurements (W is for winter). J300 is specific as to how the viscosity grade is to be shown: SAE 10W-30 is not SAE 10-30, or 10w-30, or 10W30, or 10W/30. One site that shows up as a link in many others believes that all W grade oils are measured at 0 degrees F. No test method is identified. Fortunately, no one is citing graphical determinations of low temperature!

A few websites are still caught in the Saybolt Universal Viscosity time-warp. However, most have gotten on to Kinematic Viscosity. Only a very few websites take on low-temperature viscometric tests. The one or two that I found correctly understood that cranking and pumping are different parameters.

High-temperature/high-shear rate viscosity is rarely mentioned. The one site that I found referred to it as high temp, high flow rate viscosity.

Viscosity grade recommendations are pretty much on target. The owners manual is mentioned most of all. One website recommends 30W for cars with less than 70,000 miles, 40W for engines between 70,000 and 120,000 miles and 50W for engines over 120,000 miles.

Drain Interval

Drain interval is one of the more hotly contested subjects about engine oil. Manufacturers recommendations formerly were for 7,500 miles under normal conditions (i.e., highway speeds, no dust, steady state) and 3,000 miles under severe conditions (stop-and-go driving, dusty, towing, etc.). In recent years, drain interval recommendations have been going up, in part due to improved oil quality, improved combustion processes, and fuel quality. Lubes & Greases has been involved in much of the commentary on this issue.

Drain intervals are discussed by almost all of the websites I examined. Most recommend following the manufacturers recommended drain interval. Only one site discussed in any detail what type of service cycle (normal versus severe) was involved. A few were recommending longer drain intervals; one promised 150,000 miles or 15 years! (However, the right filter and several other parameters needed to be followed.)

Oil Quality

Oil quality is generally defined by API service categories. In addition there are some manufacturers special needs which are addressed either with additional tests or with more restrictive limits on existing tests. For foreign manufacturers, there are test methods from other specification-setting groups such as ACEA in Europe and JAMA in Japan.

Most of the websites know API categories. Many will claim that the oils they tout meet more than the minimum requirements, usually by the addition of other test standards. One site recommends the use of only monograde oil due to breakdown of the polymer in multigrades which causes shorter engine life. The same site recommends using oils with C category ratings because they have more additive in them.

Other Issues

When you get past the question of viscosity (which seems to be the most frequently misconstrued property), the question of additive chemistry comes up over and over. Many sites address the ash content, zinc content and TBN (total base number) as indicative of oil quality. (More is better seems to be the usual assumption).

More than one site addresses the use of aftermarket additives. Aside from those with additives to promote, most of these seem to adhere to the position of automobile manufacturers and major oil marketers – that aftermarket additives will upset the balance of components in modern engine oils and therefore are not recommended. However, more than one site discusses the use of PTFE additives and speaks approvingly of the increased fuel economy and reduced wear provided.

Viscosity index improvers are often discussed and their function debated. Most sites report that V.I. improvers work by differential solubility (more soluble in hot oil than in cold), while one site believes that there is some sort of heat-related reaction that occurs.

Many sites try to downplay multigrades due to the polymer content and do not recommend the use of wide cross-grades. They define wide by the difference between the W-grade number and the high-temperature number in the SAE viscosity grade. For example, they calculate an SAE 10W-40 is a 30 while an SAE 15W-40 is a 25; the smaller the number, the better, their thinking goes.

Also on the subject of viscosity grade, one site declares that SAE 0W-30 cannot be used since EPA requires that an oil must be readily available before it is OK to use. (They have this one mixed up with the oil availability requirement for Corporate Average Fuel Economy claims, which does state that oils must be readily available and competitively priced before an OEM may use them for certification.)

Catching Up to Reality

So, what is the bottom line to all of this? For me, it speaks to a system that has a lot of mystery in it. Many people want to know more about oil. However, they are getting their information from sources that are out of date and perhaps even out of sync with what is going on in the industry.

For years, the lubricants industry has talked about simplifying the viscosity classification system. Weve actually tried to simplify the oil licensing system with the ILSAC designation on the container. Maybe its time to consider a website managed by the American Petroleum Institute and/or the OEMs, where the most current and correct information regarding oil quality can be located. Taking my GM pickups web registration, and linking it to this magical site would allow any owner to get the most current information about engine oil (and maybe other oils) for their car or truck. Further, oil-change locations could also tap into this source for the proper oil recommendation.

Think of the possibilities!