Synthetic oil vs. conventional oil
Both synthetic and conventional oils are lubricants, but they are made differently. Understanding those differences can help explain why synthetic oil is commonly chosen for demanding heat, cold, towing and extended-use environments.
How they are different
Conventional motor oil is refined from crude oil. Synthetic lubricant base stocks are engineered to provide a more uniform molecular structure. That gives formulators greater control over characteristics such as low-temperature flow, resistance to heat and oxidation, and film strength.
Where synthetic oil can help
Heat
Synthetic base oils are designed to resist breakdown and deposits under high-temperature operation.
Cold Starts
Good low-temperature flow helps oil circulate quickly when an engine is started in cold conditions.
Wear Protection
A durable lubricant film helps separate moving metal surfaces inside the engine.
Cleanliness
Resistance to oxidation and deposit formation can help maintain cleaner internal surfaces.
The most important rule: use the correct oil
Synthetic does not mean every oil is interchangeable. Your engine still requires the correct viscosity and performance specification. Use the owner's manual and AMSOIL's vehicle lookup to identify the appropriate recommendation.
Synthetic and conventional oils are built differently
Both types of oil can meet modern engine specifications, but synthetic base oils are engineered for more consistent molecular characteristics and are commonly chosen for better performance across temperature extremes and demanding operation.
Cold temperature
Oil must flow quickly after startup. Synthetic formulations are often selected for strong low-temperature performance when the specified viscosity allows it.
High temperature
Towing, turbocharging and hot climates increase thermal stress. Oxidation resistance and viscosity control become more important as temperatures rise.
Deposit control
A quality oil also relies on its additive system to control deposits, neutralize acids and keep contaminants suspended until they can be removed.
The specification still comes first
“Synthetic” by itself does not mean an oil is correct for every engine. The required viscosity and performance specification should always guide the selection. Then compare products within that requirement.