I enjoyed Steve Swedbergs column, Two-wheelers Love Oil Too! in your March issue, as Ive spent many a pleasant hour on or around motorcycles. Sadly, the days of the Japanese Big Four (Honda, Kawasaki, Suzuki and Yamaha) offering two-stroke powered products in the U.S. are actually behind us, as these engines tend to produce too much in the way of hydrocarbon emissions according to the EPA. Though those of us who can recall the pleasant smell of castor oil – an effective lubricant for many years – would beg to differ.

The oil injection system was a wonderful development for street riders, as it would be difficult to produce the proper gasoline/oil mix when filling up at a service station. Easier to just keep the auxiliary oil tank full and let the engine do the dispensing work. But off-road and competition riders relished the simplicity and effectiveness of a gasoline/oil mix for two-stroke engines and resulting high horsepower these engines can produce.

In other parts of the world, two-stroke engines remain an important means for powering low-cost scooters and thereby providing mobility for people who cannot afford automobiles or the latest in emissions-reduction technology. Amazing what 49 cubic centimeters of displacement can do.

Did we make a mistake in the U.S. in effectively outlawing these wonderful engines for a minimal reduction in emissions? Those of us who equate the smell of hydrocarbons with prosperity might think so.

John Fischer

Palatine, Ill.

Steve Swedberg is

wrong regarding Harley-Davidsons and their engine oil drain intervals. He stated the interval is 1,000 to 1,500 miles, which is so far from even dealer recommendations I have to say something. I have owned Harleys for years and my son works at a Harley dealer. These bikes hold a lot of oil, usually full synthetic. Intervals are 3,000 to 5,000 miles, and Ive religiously changed mine at 5K.

Matt Gudorf

Whitewright, Texas

Steve Swedberg replies: Yes, synthetic oils are available for Harley and other bikes. Regarding drain intervals, I based my information on common practice, which is that the average Harley rider only rides during the spring and summer months for recreational purposes. He usually puts on somewhere between 1,000 and 1,500 miles per year. When its time to put the bike up for the winter, the rider will often change his oil.

Militating for Synthetics

Kevin McBrides Letter to the Editor in March (Benchmark for First Made Clear, page 63) aimed to discount my statement that the U.S. Army, and not Amsoil, was the first to introduce a synthetic engine oil for both diesel and gasoline fueled vehicles/equipment and for power transmission fluid applications. His one argument is that Amsoil clearly established a concrete benchmark in 1972 by having its SAE 10W-40 engine oil meet or exceed API Service Classification SE. In my opinion and that of others, the U.S. Army military specification and its qualification process clearly established the precedent long before API had developed its certification system.

The first API certification for a synthetic engine oil by Amsoil is not being challenged, but one cannot summarily dismiss the success of the Aberdeen Proving Ground Purchase Description Number 1 (APG PD #No. 1) engine oil, and later the MIL-L-46167 specification in satisfying all the commercial and military diesel and gasoline fueled engine systems that comprised the Armys ground fleet. This occurred well before the 1972 introduction of Amsoil 10W-40 SE engine oil, and was documented in the Army Fuels and Lubricants Research Laboratory report AFLRL-71 (AD-A023 613) published in 1975 and later in the SAE Paper 892051. Both of these papers stated The arctic lubricants are diesters, synthesized hydrocarbons, or blends of each, which have demonstrated exceptional performance in engine dynamometer and field Army arctic operations since 1967.

Further, one can seriously question whether the Amsoil product would have met (1) all the militarys cold-cranking requirements, or (2) the militarys high output 2/4 cycle diesel engine requirements.

My initial statement that generated the letter from Mr. McBride was the U.S. Army had developed and fielded a synthetic engine oil for both diesel and gasoline fueled vehicles/equipment and for power transmission fluid applications much earlier than 1972. This is certainly valid although it lacks the one concrete benchmark claimed by Mr. McBride, who chooses to ignore the five-plus years of its completely satisfactory use in a wide variety of engines.

One additional point: Mr. McBrides letter states, the Army experimented with synthetic oil in 1967. The Army initiated development of APG PD #No. 1 n 1960, not 1967. As

well, I published a paper in Lubricants World in January 2000 (http://www.melepera.com/documents/Synthetic%20Automotive%20Engine%20Oils-A%20Brief%20History.pdf) that made the identical claim as in my initial letter (i.e., the Army was the first to field a synthetic engine oil.). No adverse or critical comments like those from Mr. McBride were ever generated that I am aware of.

Maurice E. Le Pera

Le Pera and Associates

Harrisonburg, Va.

LubesnGreases welcomes letters from our readers. Letters must be signed and may be edited for length. Mail to Editor, LubenGreases, 7389 Lee Highway, Suite 300, Falls Church, VA 22042 USA, or e-mail info@LubesnGreases.com.