Synthetic motor oil offers many advantages for the big bore Harley-Davidson motorcycles. Aside from being air-cooled, Harley big bores tend to run higher cylinder temperatures because of the long stroke and comparatively smaller bore. This increases the swept area in the cylinder and piston speed for any given RPM . ;

Big twins that are operated in the southern areas of the country where outside temperatures are higher or are used in a lot of stop and go city driving will see elevated temperatures, especially in the rear cylinder. All of these factors put increased demands on the engine oil. Compared to conventional petroleum oil, synthetic motorcycle engine oil offers many advantages. ; ;

High grade synthetic oils manufactured from PAO (polyalphaolifin) base stocks offer dramatically better wear protection and excel in high and low temperature extremes. In cold temperatures, synthetic motor oils provide near instant oil pressure and easy cranking during starts. At high temperatures that would have conventional petroleum oil oxidizing at a rapid pace with the attendant wear, sludge and deposits this causes, synthetic oils uniform molecular structure runs clean and cool. ; ;

Synthetic motor oils dissipate heat faster often dropping cylinder temperatures twenty to fifty degrees. Synthetic oils help maximize fuel economy and increase horse power by reducing friction and drag considerably compared to conventional oils ; ;

Amsoil inc. introduced the first American petroleum Institute rated motor oil in 1972 and today is considered the world leader in synthetic motor oils and lubricants. ; ;

By: Larry Crider, ; lubrication specialist ;