Anyway, for those who might be harboring their own comments but didnt bother to write, heres a peek at some of the recent mail.

Two PC-lls?

Regarding Septembers column on GF-6, Scott Richards of San Antonio wrote, The new format where the first page of most major articles is super-small print is very difficult to read, at least for me but Im old. He added, Steve, you make no mention that there will be two PC-11 heavy-duty engine oils for API CK, high HTHS and low HTHS.

First, I know what you mean about small print! I cant decide whether my bifocals are bad or my eyes are getting worse. At any rate, I have to take my glasses off to read the computer screen and then blow up the images.

Second, youre right that I didnt mention PC-11 viscosity issues. I was trying to focus solely on GF-6 (passenger car engine oils) and thought that if I raised the PC-11 issue it would confuse an already complex issue even more. Ill be addressing the whole high-temperature high-shear viscosity issue for PC-11 separately.

Synthetic Bias?

Sometimes readers ask for clarifications that go beyond a simple one-liner. These are often the most interesting, and challenging. For example, Norman Bauer of Anna, Ill., raised a number of issues that are dear to the hearts of those who view synthetics as the answer to superior performance and longer drain intervals: I can[t] understand why you keep covering the same subject of oil change interval. Although you mention synthetics and get technical by explaining where oils are grouped, you fail to expound on the true advantages of man-made synthetic lubricants. Perhaps 40 years of being in the industry has you biased to conventional fluids.

Norm went on to note that Mobil 1, Amsoil and others have extended oil change intervals beyond the normal 7,500 miles for many years. He credited this to better additive chemistries, as well as the use of high viscosity index API Group III [and IV] base oils. Some manufacturers can use inexpensive additives, less additives and still meet the API requirements, he pointed out. Others can develop high-quality lubricants that cost a bit more.

Tell people that the best quality lubricants cost more and provide more protection, he urged. There will be no sludge or build-up in the engine. It will provide better lubricity while improving fuel efficiency. Norms parting shot: Perhaps you are concerned about the legal ramifications if you promote extended change intervals.

My response: You are astute as to the real performance needs of engine oils, namely additive chemistries and base stocks. However, I think you might be misjudging me on the bias issue. I have no skin in the game on any base stock. Ive worked on formulations that are mineral based, semi-synthetic and synthetic.

Base stocks are categorized for purposes of testing and interchange. The first three API Groups are based on degree and type of refining while Group IV is reserved for polyalphaolefins. Group V is a catch-all for all the other fluids that have found their way into engine oils.

Group III is a synthetic because of an advertising arbritration which defined it as such. This decision was the result of challenges to Castrol advertisements claiming synthetic status for an engine oil made with Group III base oil. The argument was that Group III could be made by severe refining or by polymerizing wax. Since the polymerization process is similar to PAO processing, it was accepted as synthetic.

Most oil marketers shifted to using Group III, versus PAO-ester combinations, for cost reasons. In fact, there is still a cost differential between the two favoring Group III (but not by much). Esters were included in PAO formulations because additives are not very soluble in PAO alone and require esters to help keep additive components in solution.

Norm, its not my place to make recommendations about one product versus another. Synthetics offer some great advantages in terms of longer drains but at a cost disadvantage. Some vehicles are driven for lots of miles in a year and others are not. Some people like the idea of going longer between oil changes while others see timely changes as cheap insurance to protect what is, for most, the second-largest investment in their life (a home being first).

I try to bring all of the issues to the surface and give people a chance to make their own decisions. After 40 years in the business, Ive seen quite a few oils and chemistries used. Theres no question that a well-formulated engine oil will provide satisfactory lubrication. How the engine survives is dependant on a lot of things besides oil – like driving cycle, climate, how the vehicle is used, and so on. Will synthetics make everything go better? They can play a part but they are not the only answer. Sorry Norm.

No Drains Ever?

Readers, I must note that many of the questions and comments regarding synthetics come from Amsoil dealers. Amsoil engine oils are formulated to have all of the necessary pedigrees (ILSAC GF-5, API SM) to meet current industry requirements. The company sells its products through a network marketing or multi-level distributor approach, which means each seller is an independent business.

I enjoyed some back-and-forth with Ed Newman, Amsoils advertising director in Superior, Wis., who dropped me a note asking, You mention synthetic oil marketers who make aggressive claims of up to no drains at all and much better performance. I was curious who you were referring to here? I do not recall seeing it myself, and I pretty much pay attention to these things. He added, The way the sentence is structured implies that the better performance is as bogus as the no drains at all claim. Just a little uncertain what you mean here.

As far as that no-drain recommendation is concerned, that was a comment from a quick-lube operator who just happened to be pushing synthetics, on the Automotive Oil Change Associations LinkedIn discussion line. (There is also a thread, running through a lot of conversations about oil change intervals, that advocates regular used oil sampling.) As well, I observed that a few of the Amsoil distributors get pretty aggressive in their recommendations. They sometimes go way past the companys official drain interval recommendations in posts on various websites.

Ed responded, In our case, we warrant engines when our recommendations are followed. Dealers who promise more are going out on a limb there. On the internet it gets a bit Wild West-like but we have always had in-house personnel doing follow-up on web violators and policy violators. When a dealer makes outrageous claims or violates our policies about advertising [or] pricing, other dealers will put on a posse badge and bring them to the sheriff. It has been a fairly effective means of monitoring, and while not perfect it pretty much weeds the most visible problem websites.

Yes, many of our dealers are exuberant but fortunately most have at least one foot on the ground. Our literature is a bible for these, hence we take great pains to be very careful in our claims and recommendations. And, unlike some companies, what we say privately at meetings always corresponds to what we put in writing.

Cold Comfort?

Other notes delve into the mysteries of technical issues, such as low-temperature viscometrics. Ive not seen that the issue of pour point elevation of used (even slightly) engine oils had been resolved, so am wondering if I missed it, one reader asked. Is there a specific focus/emphasis on this in the new ILSAC GF-6 specification? Perhaps Im too close to the issue but … it sure is one that anyone who has to contend with low-temperature starts in the morning (minus 40 in Minneapolis!) would want reassurance.

Good question! Actually, the pour point elevation issue is covered in both ILSAC GF-5 and the draft GF-6 specification. Formulators can measure the end-of-test oil from the Sequence IIIG engine test, or they can use an oil bench oxidation test called the ROBO (named after Ray Romaszewski of Evonik Oil Additives, the scientist who developed it). ROBO uses a reactor and bench test to mimic the viscosity increase from the time-consuming Sequence IIIG. Officially known as ASTM D 7528, it is an alternative to the IIIG-A, which often can require multiple runs to determine low-temperature performance. Obviously, the ROBO bench test is much more cost effective than running the IIIG.

Lets look more closely at this low-temperature viscosity test, which checks the aged oil samples Cold Cranking Simulator (CCS) viscosity against that of the oils original viscosity grade. Remember, CCS determines the engines ability to crank at startup; if the CCS is too high, the engine wont turn over.

If the ROBO test finds the CCS viscosity measurement is less than or equal to the maximum specified for the original viscosity grade, you must run ASTM D4684, the Mini-Rotary Viscometer TP-1, which measures the oils ability to flow at low temperatures. This is critical, because if the engine cranks but the oil doesnt flow, the result is engine failure.

Alternately, if ROBO finds the CCS to be higher than the maximum specified for the original oil, you have to run the MRV TP-1 at 5 degrees C higher temperature (i.e., that of the next-higher viscosity grade in SAE J300).

The end-of-test ROBO sample must show no yield stress in the D 4684 test, and its D 4684 viscosity must be below the maximum specified in SAE J300 for the original viscosity grade, or the next higher viscosity grade, depending on the CCS viscosity, as outlined in the above.

While its clear that a used oil cannot typically perform as a new oil, this requirement puts limits on how much it can deteriorate.

It is important that we all understand the issues and tests which can make or break an oil, and by extrapolation, an engine. The ROBO is such a test.

Correct Me if Im Wrong…

Finally, Bill Buscher, from San Antonio, sent comments on Septembers column: I noticed some information that was incorrect concerning the Sequence IVA valvetrain wear test. In the article you state that the current Sequence IVA is sponsored by Toyota and is apparently still good to go, which isnt correct.

Bill is absolutely right, and we were quick to publish a correction last month; the Sequence IVA was sponsored by Nissan, and Toyota is developing its successor, the IVB. Ill be writing more about that, too. Todays message for readers is to be sure to let me know if you see factual errors. I rely on my computer, my research and my contacts in the industry to keep me on the straight and narrow. However, sometimes I may get the facts tangled or my fingers dont hit the keys I think theyre hitting. In either case, its better to be corrected than to be blissfully unaware of errors.

Thanks to these and other readers, Ive gotten a lot of messages which cause me to think more about how I communicate. I hope that you are getting what you need. And by the way, keep those cards and letters coming!