Aircraft maintenance needs fluctuate based on the climate where the plane in question logs most of its hours. Pilots, servicemen, and businesses that tune-up commercial and private aircraft utilize different techniques when it comes to making sure planes — regardless of the environment in which they fly — are safe, well maintained, and running smoothly. One crucial element in ensuring the health of an aircraft is engine maintenance and upkeep; a major component is the use of the proper oil, and an appropriate service/oil change schedule.
Choosing the right oil and viscosity grade for an aircraft’s main operating environment is critical to a successful maintenance program. Viscosity is, in layman’s terms, a measure of how quickly an oil flows at a given temperature. The lower the viscosity, the more quickly the oil will flow at startup. While most aircraft owners understand the basics of lubrication, the difference between viscosity grades, and the benefits of each, often creates some confusion. As the aviation industry begins to further understand the science behind multigrade aviation oil — as well as the key features and benefits of these products — those who fly or care for airplanes will be better equipped to improve engine performance and potentially extend the operating life through more specialized engine maintenance, whether in the dog days of summer or the dead of winter.
Multiviscosity oils and Aviation 101
Over time, multiviscosity oils have become the standard for nearly all automotive, trucking, and heavy-duty equipment applications, but have yet to take a strong foothold in aviation. Prior to the increase in popularity of multiviscosity products, the only oil that was available for use on aircraft was monograde, otherwise known as single-grade or straight grade. These monograde oils have inferior lubricating properties because the difference in viscosities varies too much between temperature extremes. As engineers and mechanics sought improved lubrication, scientists formulated oil that would impart enhanced lubrication properties in freezing cold temperatures and boiling hot weather, by utilizing polymers. These polymers — the building blocks of multiviscosity oils — not only allow cold temperature startup capabilities, but also provide increased protection in high temperature climates.
While the automotive industry was the first to overwhelmingly adopt the use of multiviscosity oils, and continues to utilize the technology today, only half of the aviation industry has made the switch. Despite their slow adoption by aircraft owners, operators, and mechanics, multiviscosity aviation oils are not new — the first, Phillips 66 X/C 20W-50, was introduced in 1979. Even with nearly 30 years of proven performance in the most demanding applications, not everyone understands the unique performance benefits of multiviscosity aviation engine oils.
Multiviscosity oil stands up to the extremes
The most basic principle behind the effectiveness of multiviscosity aviation oils in any climate is the fact that the product — offering supreme protection — can flow smoothly at low temperatures, yet also properly protect engines in the heat. As most anyone who uses engine oil on a regular basis knows, all lubricants get thinner (or less “viscous”) as their temperature increases, which is the process that allows lubricants to flow freely through an engine. What many people don’t know is that multiviscosity oils are composed of a small amount of polymer, which is designed to provide the best high-temperature protection, along with base oils that offer the greatest cold-temperature properties. This unique design is what makes these oils superior to monogrades, and the smart choice for aircraft in