Several people have asked me for my advise on the use of engine oil. There are many articles on the web regarding this issue. Questions are asked such as: Should I use regular motor oil or Motorcycle oil in my two stroke or four stroke motor? Can I use regular motor oil in my wet Clutch? Will the clutch slip with regular motor oil installed? Is it ok to use regular motor oil in my engine that also lubricates the gears for the transmission? Do I have to use motorcycle oil or can I use regular motor oil in my motorcycle?

Oil uses detergent additives to combat combustion by-products. Burning gasoline produces acids, moisture, soda, ash and other contaminants. The detergent fights these by-products, inhibiting their buildup as sludge and varnishes. Since most old Triumphs do not have the luxury of the use of a modern micro oil filter, regular oil change is a necessity. In addition to removing the oil in the crankcase and oil tank, remember to empty the primary case oil to stop varnishes from building on the clutch assembly. Repeated oil changes assure a clean engine. The benefits of using synthetic oil become somewhat insignificant and too costly if the oil is changed every 3000 miles and the vehicle does not undergo extreme conditions. This is my opinion. After reading many documents for and against the use of motor oil in motorcycles I have come to the following conclusions.

There are several oils on the market made significantly for motorcycles. My research has come to the following conclusions of Motorcycle oils verses Regular Motor oil usage: Oil development has progressed a long way since motorcycles have been in use. Improvements in additives and government restrictions have leveled the playing field between Motorcycle oil and Regular (car) oil. Small, high revving car motors have made the oil industry develop oil similar, if not the same, oil as what motorcycles require. But, there are still some things to look out for when purchasing the oil that is right for you. Use only high detergent, premium quality motor oil certified to meet API Service Classification SF or SG. These Classifications are noted on the containers. Do not use oils with friction modifiers such as graphite or molybdenum additives as they may adversely affect clutch operation. The new "energy-conserving" motor oils have these "friction modifiers". The use of this oil may cause clutch slippage. Since that is a legitimate concern when selecting an oil for your wet clutch motorcycle, it is best to use only oils which are NOT considered "energy-conserving for motorcycles with wet clutches." Read the back of the container. It clearly identifies this. In general, only the very lighter oils, like 10w30, 10w20, 5w20, are energy-conserving . All 5w40, 5w50, 10w40, 15w40, 15w50, and 20w50 oils, which I have found, are not energy-conserving and can be recommended for general motorcycle use.

These lighter oils should also not be used the motors that include the transmission gears in the engine oil. They will not provide the damping required for the gears.

Points of interest noted in my research:

Oil is used to dampen the vibration and reduce friction between metals in motors. Oil coats and fills the voids of metals so that they will not actually meet. The hydrocarbons are what give oil its properties. The best oil is made up of hydrocarbons of equal size. When these hydrocarbons break up into smaller sizes, this is called Viscosity Break down .

The most significant oil viscosity brake down of petroleum-based oil occurs during the first 800 miles or less. Synthetic oil viscosity breaks down slower than petroleum-based oils. This is due to its greater uniformity of hydrocarbons.

Many Synthetic Oils are made from Petroleum oil. Standard Petroleum oil is just further processed for uniformity of hydrocarbons. Most manufacturers will not identify it on the container.

Viscosity is the rate that oil flows. The higher the grade, the thicker the oil and the better it dampens vibration. Multi-grade oil ratings are tested at two temperatures, 40 degrees and 100 degrees.

If you use oil that is too thick, the engine oil pump will not move it effectively throughout the engine. Passages or cracks may be too small for oil to move thru and properly lubricate.

Long-chain polymers, an oil additive, are added to the oil to give it the multi-weight characteristics. These polymers are coiled up when the oil is cold and straighten out when hot. This action changes the charactoristics of the oil at the different temperatures.

The following links will direct you to articles that will give much more information on this subject: