I liked this part:
Quote:
A number of years ago, straight grade engine oils, especially SAE 30 and SAE 40, were the most prevalent viscosity grades used by most consumers. SAE is considering adding either two or three new viscosity grades to the SAE J300 Viscosity Classification that was described previously. (15) The reason all of this is occurring is because much attention is being paid to improving fuel economy and energy efficiency. Governments are pushing automotive and industrial OEMs to find ways to improve the efficiencies of the vehicles and equipment they produce. It is not completely surprising that lubricants have been considered as a means to decrease fuel and energy consumption. As viscosity is a measurement of the internal resistance of a fluid to flow, if the viscosity is decreased, then so is the internal resistance. Therefore attention is now being paid to decreasing the viscosity of various lubricants to reduce their detraction from efficiency. Improved efficiency results in less energy consumed, which results in lower emissions released into the environment.
I'm not against lower viscosity fluids (I use 0W20 in my Prius), but it should be understood why we use them.
I'm against the B.S. showing up in many BITOG threads that lower viscosity is to decrease wear.