A high-quality lubricant is engineered to withstand the effects of these reactions longer, but there are limits.
Many people already know that severity of service puts additional stress on engine oil, but we don’t talk much about the effects Father Time has on oil. Chemical and physical changes are occurring in your engine oil from the day it is installed in your vehicle, even when the vehicle is not in use. Just like inside your body, there are a number of different reactions occurring inside your engine that impact its overall health. Like eating too many Big Macs and drinking too much Coca-Cola can accelerate reactions that can harm your health, contaminants introduced into your motor oil can accelerate reactions that can harm your engine.
AMSOIL Signature Series Synthetic Motor Oil is recommended for 25,000 miles in normal service. I’ve driven only 18,000 miles since last spring when I changed my oil, so why do I need to change it after a year in service? The oil level is full, so why not just keep driving and get the full 25,000 miles out of the oil? It may be possible through oil analysis, but without verifying a clean bill of health, the oil must be changed to ensure the vehicle is protected.
Motor oil is continually subjected to a variety of forces and contaminants that degrade the oil’s quality until, ultimately, fresh oil is required. Forces such as oil-pump shear and contaminants such as combustion by-products, fuel, water and coolant all affect the expected life of motor oil.
Combustion by-products pass by the rings, seep into the oil sump and reduce motor oil life. Higher concentrations of by-products in the oil affect the rate at which chemical reactions occur, but the amount of time combustion by-products are in contact with motor oil also has an effect. The acids and free-radicals created when burning gasoline or diesel fuel accelerate chemical reactions that degrade motor oil. When you install brand new oil and start the vehicle, these reactions begin and continue, to an extent, even when the vehicle is not operating. These chemical reactions result in increased viscosity, oxidation and nitration levels in the motor oil.
Fuel dilution is another major cause of motor oil degradation. Vehicles driven for short trips that do not reach normal operating temperatures don’t get hot enough to evaporate fuel from the sump. Gasoline trapped in the oil sump thins the oil and promotes chemical reactions that degrade the oil. This phenomenon is more pronounced in diesel applications because diesel is less volatile and does not readily evaporate, reducing engine oil viscosity as fuel builds up in the oil sump.
Water and glycol contamination tend to occur together, but water without glycol is also common. Glycol, a common component of antifreeze, is a particularly damaging contaminant and is estimated to account for 60 percent of all engine failures. Antifreeze can enter the engine through a leaky head gasket, faulty oil cooler or other area. It doesn’t take much glycol to degrade motor oil, reduce lubricity and react to thicken the oil to the point where the oil pump cannot supply enough oil to the engine for proper lubrication. Once that happens, the engine comes to a screeching stop.
Water is usually the primary source of trouble for oil in a vehicle that is only driven occasionally, such as an RV or a classic car. In those cases, water from condensation can build up in the crankcase and remain there for long periods if the engine is not brought up to operating temperatures on a regular basis. Once an engine is warmed up, the water evaporates and is removed from the engine by the crankcase ventilation system. If not, the water will degrade the oil and potentially promote corrosion within the engine.
Other forms of contamination that affect oil life include questionable oil additive products, excessive soot from a poorly running diesel and residue left by pressurized injector cleaning. These contaminants all affect engine oil life over time. As vehicles age, the chance of encountering some or all of these contaminants increases. Since these reactions start with the turn of a key and continue even when the engine is not running, there has to be a time limit placed on lubricant life for good vehicle protection. Without a qualified used oil analysis program in place, a conservative limit is used to ensure the oil is changed prior to becoming critical; hence the one-year limit on AMSOIL Signature Series Motor Oil. Keeping your vehicle working optimally through good preventative maintenance also helps to keep contamination to a minimum, but it does not eliminate it altogether.
The bottom line is that after being used for one year, there are just too many possible chemical reactions to guarantee protection without used oil analysis for verification. If you are using an AMSOIL product, you have proven that you care about your equipment. Making wise choices and following proven techniques is the next step in becoming a lubrication expert. If it is true that information is power, then everyone should be able to explain how contamination affects engine oil life over time on a quest to reach Amsoil superhero status.
service intervals and high filtering efficiency and capacity maintenance managers are looking for.
10W-40 Synthetic Motorcycle Oil
Formulated to thoroughly clean varnish, gums and insoluble debris in two and four-stroke gasoline-powered small engines and power-sports equipment fuel systems, restoring peak performance. Effectively addresses performance issues related ethanol, water and dirty pump gas. Stabilizes fuel between and during short-term storage periods.
improve start-up performance and eliminate engine ping or knock for increased power at low-rpm operation. It contains detergents that help maintain cleanliness of combustion chambers and fuel delivery systems for optimum performance. At the recommended treat rate, it does not harm catalytic converters or oxygen sensors and is compatible with other AMSOIL fuel additives. Motorcycle Octane Boost is available in the U.S. only at this time.
