5. What does the letter “W” mean in the oil specifications?

The letter “W” stands for “winter”. The SAE (Society of Automotive Engineers) classifications characterize the viscosity at low and high temperature of the lubricant.
The grade is given by two numbers separated by the letter “W” (meaning winter). The first number, followed by w represents the low temperature viscosity, 5W, 10W, 15W….the lower this number, the more fluid the oil at low temperature, the easier the engine starts. The second number gives the high temperature viscosity - 30, 40, 50 etc. The higher this number, the more viscous the oil is when hot. If there is no “W”, the oil is probably a mono-grade oil and is designed for special usage conditions. It will probably not be suitable for modern engines, which require
multi-grade oil for complete protection. You really need to read the specifications in order to understand what the particular oil is like. MILEX always uses the international marking system to identify is products.
A lubricant that’s too thick, or worse, not thick enough can cause major damage to the moving parts of an engine. The SAE sets the viscosity standards for these oils.

6. What is the advantage of using Multi-grade oils?

Multi-grade oils have the advantage of providing quick start-up protection when the engine is cold. In a cold engine the 15W or 20W multi-grades will start to flow and circulate much quicker providing better protection in a cold starting engine. Initial start-up and the first few minutes of operation is a very critical time when the majority of the engine wear is often experienced. In addition to the initial start-up advantages, engine builders have proven that multi-grade engine oils reduce oil consumption and critical engine area deposits when compared to mono-grade oils.

7. What is the shelf-life of your products?

The shelf life of most oils and greases manufactured by us is
two years from the date of manufacture, provided that the
oils are greases are properly stored in their original,
un-opened containers.