I found this description from http://www.freepatentsonline.com/4515680.html
Quote:
Historically, naphthenic lubricating oils have been the lubricating oils of choice on a cost/performance basis. This has been particularly the case in formulating highly viscous oils used in heavy duty applications such as railroad and marine diesel engines. It has been the experience in the art that the naphthenic lubricating oils have the capability of dissolving and/or softening significant quantities of the semi-solid carbonacous decomposition products which form in crank cases under severe operating conditions. The semi-solid carbonacous components formed on the cylinder walls and suspended in naphthenic lubricating oil in the crank cases of diesel engines tend to be softer than the corresponding carbonacous products formed in paraffinic lubrication oils under identical operating conditions. By reason of their softer nature, the deposites formed from naphthenic lubricating oils cause less wear on moving engine parts. It is the belief in the art that diesel engines have a longer operating life when lubricated with naphthenic lubricants than is the case with paraffinic lubricants. Specifically, it is believed that the incidence of piston ring breakage is lower when naphthenic lubricating oils are employed.
By a quirk of nature, naturally occurring crude oil containing significant fractions of naphthenic hydrocarbons in the lubricating oil range are found largely within the continental United States and Venezuela. Crude oils produced in other oil producing areas of the world have relatively lower concentrations of such naphthenic hydrocarbons. Accordingly, as the worldwide demand for naphthenic lubricating oils is increasing, the available supply of crude oils containing significant concentrations of the desired naphthenic hydrocarbons is decreasing. It is thus seen that a shortage of naphthenic lubricating oils is developing.
Do we assume that PCMO is based on paraffinic lubricating oils and HDMO/diesel oil is based on naphthenic lubricating oils?
Thanks!
Quote:
Historically, naphthenic lubricating oils have been the lubricating oils of choice on a cost/performance basis. This has been particularly the case in formulating highly viscous oils used in heavy duty applications such as railroad and marine diesel engines. It has been the experience in the art that the naphthenic lubricating oils have the capability of dissolving and/or softening significant quantities of the semi-solid carbonacous decomposition products which form in crank cases under severe operating conditions. The semi-solid carbonacous components formed on the cylinder walls and suspended in naphthenic lubricating oil in the crank cases of diesel engines tend to be softer than the corresponding carbonacous products formed in paraffinic lubrication oils under identical operating conditions. By reason of their softer nature, the deposites formed from naphthenic lubricating oils cause less wear on moving engine parts. It is the belief in the art that diesel engines have a longer operating life when lubricated with naphthenic lubricants than is the case with paraffinic lubricants. Specifically, it is believed that the incidence of piston ring breakage is lower when naphthenic lubricating oils are employed.
By a quirk of nature, naturally occurring crude oil containing significant fractions of naphthenic hydrocarbons in the lubricating oil range are found largely within the continental United States and Venezuela. Crude oils produced in other oil producing areas of the world have relatively lower concentrations of such naphthenic hydrocarbons. Accordingly, as the worldwide demand for naphthenic lubricating oils is increasing, the available supply of crude oils containing significant concentrations of the desired naphthenic hydrocarbons is decreasing. It is thus seen that a shortage of naphthenic lubricating oils is developing.
Do we assume that PCMO is based on paraffinic lubricating oils and HDMO/diesel oil is based on naphthenic lubricating oils?
Thanks!
