in engines required to meet 1994 emission standards.

CH-4 is for use in high-speed four-stroke engines designed to meet 1998
exhaust emission standards. CH-4 oils are specifically compounded for use
with diesel fuels ranging in sulfur content up to 0.5 percent weight. It can be
used in place of CD, CE, CF-4, and CG-4 oils.

CJ-4 is for 2007 and newer diesel engines. It was developed to address
special concerns regarding emission control engines and their operation on
ultra-low-sulfur diesel fuel (ULSD).

SAE stands for Society of Automotive Engineers. Motor oils have SAE
grades, or numbers, that indicate viscosity. In other words, the SAE numbers
tell you the thickness of the oil. The higher the number, the thicker the oil.

Q What does a viscosity rating of 5W30 mean?

A W signifies its winter rating, showing that it will perform well in cold

weather. The number and letter designation signifies the winter flow weight
of the oil. Colder temperatures tend to thicken oil so that it flows more
slowly, which can be disastrous to your car’s engine. Therefore, in mixing the
oil, the refinery adds a chemical (or package) that adjusts and stabilizes the
oil at the lighter weight when it gets cold outside. Consequently, it will flow
more easily and freely at subzero temperatures. The higher number at the end
of the viscosity rating represents the weight the oil adjusts to at higher
temperatures. High temperature tends to break oil down and affects its
lubricating ability. Therefore, the refinery adds a chemical package that
toughens the oil to stand up and maintain enough body in order to perform its
job at high operating temperatures.