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Letters to the Editor


All Wet about PAG

Dear LubesnGreases,

I would like to comment on Februarys article Green Lubes for Vessels, by Mark Miller of Terresolve Technologies. There are some outright fallacies in the statement about polyalkylene glycol fluids. He states that they can take years to biodegrade, can be very toxic and have poor water tolerance. Actually, the exact opposite is true. Water soluble PAG fluids such as Dow Chemicals Ucon Trident AW 32 are very readily biodegradable (up to 81 percent biodegradable in 28 days per OECD 301F); are rated by the U.S. EPA as Practically Non-Toxic; and have no chemical reaction to water, as do vegetable oils and vegetable esters. In fact, chemical reactions with water to form acids that attack seals, hoses and sensors are the Achilles heel of natural and synthesized triglycerides, along with poor oxidation and thermal stability.

Water soluble PAGs and products such as Ucon Trident or BASF Plurasafe TC can handle about 100 times the water contamination of any other oil and still provide excellent lubrication. Since these fluids are water soluble, there is no saturation point, but the viscosity and performance will diminish gradually as water content increases. Transport Canada, which polices the Canada Shipping Act in Canadian waters, considers PAG lubricants as non-pollutants and non-toxic due to the fact they will not adversely affect aquatic birds and mammals, as will even vegetable oil. This became very evident when a large Canola oil spill in Vancouver, B.C., harbor resulted in over 2,000 seabird fatalities.

There is a reason why the U.S. EPA included PAG fluids as one of three types of Environmentally Acceptable Lubricants or EALs, the others being vegetable oils and synthetic esters. The criteria were that the fluid had to be readily biodegradable, meaning biodegradability of 60 percent or greater in 28 days, and very low aquatic toxicity. These PAG fluids pass with flying colors and are also the only lubricants to pass all five stages of the non-sheening test in 40 CFR 435. They are not a violation of the Clean Water Act, not subject to oil spill regulations under the Oil Pollution Act of 1990, and not classified by the U.S. Coast Guard as oil (as are ALL mineral or vegetable oils and esters).

This restates the truth as to the real environmental benefits of PAG fluids.

Jim Burton, Coast Lubricants Ltd., Nanaimo, B.C.

Bragging Rights on Recycled Oil

Dear LubesnGreases,

Januarys Publishers Letter has a quote from Thom Smith stating that NexGen engine oil is the first branded rerefined oil by a major marketer. I dont know who was first, or how Valvoline defines major marketer, but I do know that 76 Products Co., then owned by Unocal, first introduced its Firebird line of rerefined lubricants (PCMO, HDEO and industrial hydraulic oils) in late 1994 under the 76 Lubricants brand. That brand today is owned by Phillips 66 Co., and we continue to offer rerefined lubricants today. I also know that Chevron and Arco also offered rerefined lubricants in the 1990s. And others have certainly introduced them prior to 2011.

Allan Perry, Phillips 66, Ponca City, OK

Where Rerefined Oil Belongs

Dear LubesnGreases,

I noticed that your chart on API Base Oil Groups on page 14 of the January issue contained an error. Rerefined base oil is definitely not in API Group V. Most rerefined base oil in North America is Group II, as you know. (Not even sure about whether naphthenics belong in Group V.)

Steve Haffner, Infineum LLC, Linden, NJ

SAE 16 a Puzzle

Dear LubesnGreases,

Let me see if I have this straight. Steve Swedbergs Automotive column in January shows the following high-temperature high-shear (HTHS) limits for the new SAE 16 viscosity grade:

SAE 16 will be 6.1 to <8.2 cSt at 100 C and ≥ 2.3 HTHS.

SAE 20 will be 6.9 to <9.3 cSt @100 C and ≥ 2.6 HTHS.

It appears there is overlap. Will some products currently labeled SAE 20W or 20W-20 have to be relabeled as 20W-16? Will the marketer be able to choose the grade he prefers, if he meets the requirements for both?

Blaine Ballentine, Central Petroleum Co., Walcott, IA

Steve Swedberg responds:

I know that the SAE 16 grade is confusing. Here is what the footnote says regarding when to use SAE 16:

Since there is overlap between the kinematic viscosity ranges of SAE 20 and SAE 16, an additional labeling requirement was included in SAE J300. For oils falling in the overlap region, the high temperature viscosity grade is determined by the HTHS viscosity, where only the highest grade satisfied shall be referred to on the label. For example, if the kinematic viscosity of an engine oil is 7.80 mm2/s at 100 C and the HTHS viscosity at 150 C is 2.64 mPas, it must be labeled SAE 20.

Basically only the highest grade is reported. This is like the low-temperature viscosity, where only the lowest grade attained is shown. So an SAE 5W will also meet SAE 10W but only SAE 5W is shown.

As for what marketers will do, most are saying that they will stay with current designations. The volumes for SAE 16 are projected to be very small for some time. Only Honda is going to use it now. Other OEMs might think about it, but engine designs are usually locked in years before they appear on the market.

Bottom line: Dont be looking soon for a flood of SAE XW-16 oils on your big-box shelves.

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