13 Apr Reasons why motor oil must be changed:
AMSOIL synthetic motor oil helps you feel confident your engine is protected and can deliver extended drain intervals. However, every motor oil loses its potency and must be replaced to ensure peak engine performance.
What happens to motor oil over time and why you periodically need to change your oil.
Losing the base – base oils are the backbone of the finished lubricant that ends up in your engine. Over time, they lose effectiveness due to the following factors:
- Oxidation – The interaction between oxygen molecules and motor oil molecules naturally leads to chemical breakdown. Just as oxygen causes exposed metal to rust, it breaks down base oils and reduces oil’s effectiveness.
- High heat – Today’s engines run hotter than ever before, with temperatures up to 235 degrees F and even higher if towing or hauling.
- Moisture – Vehicles are subject to temperature swings even when parked. Those temperature swings cause condensation to form inside the engine, leading to water contamination. Leaving the vehicle parked for extended periods or taking short trips that don’t allow the engine to fully warm up, allows water to remain in the oil rather than evaporating and exiting through the tailpipe. Water can lead to the formation of sludge – another reason to change the oil.
- Fuel Dilution – Fuel can wash past the piston rings and contaminate the motor oil, causing it to lose viscosity. Frequent short trips that don’t allow the oil to reach operating temperature can be especially problematic because the fuel won’t volatilize and exit through the PCV system. Excessive fuel dilution leads to sludge and varnish, requiring you to change oil more frequently.
- Viscosity Loss – A lubricant’s viscosity is its most important property. Viscosity has a direct bearing on engine wear protection and your engine is designed to operate best using a motor oil of a specific gravity (5W-30).The intense pressure the oil bears as it’s squeezed between moving parts, like the piston ring/cylinder wall interface, can tear apart, or shear, its molecular structure, leading to viscosity loss. Suddenly, the 5W-30 motor oil your engine was designed to use is now essentially a 5W-20 oil ( a thinner oil) and wear protection may be compromised. It’s now time to change your oil.