The following excerpt is found in an AAA Oil Quality Fact Sheet and was written by John Nielsen, Managing Director, Automotive Engineering
Oil quality comes down to the oil’s ability to withstand the extreme conditions that exist inside an engine. The greater the resistance to deterioration, the greater protection of vital engine components.
Is synthetic oil better for all vehicles?
In AAA’s tests, synthetic oil outperformed conventional oil by an average of 47 percent. While any oil that meets the vehicle manufacturer’s standards is safe to use in your vehicle, synthetic oil will offer better engine protection.
Is AAA recommending that drivers switch to synthetic oil?
It’s really a personal choice. If your budget allows, synthetic oils will offer additional protection for your vehicle, particularly if it frequently tows heavy loads, operates in extreme temperatures or is driven in stop-and-go traffic.
Will conventional oil damage a vehicle’s engine?
No. A conventional oil that meets a manufacturer’s specifications will not harm a vehicle’s engine.
Does using synthetic oil mean you can extend the interval between oil changes?
Drivers should always follow the oil change interval provided by their vehicle manufacturer. This can be found in the owner’s manual, or the on-board oil life system.
How do you know what type of oil to use in your vehicle?
Your owner’s manual is the best resource. This will provide not only the viscosity required for your operating conditions, but the specification. Always ensure that any oil used in your engine meets the internal performance standards required by the vehicle manufacturer.
Source: John Nielsen has more than 25 years of experience in the automotive industry. Starting as an automotive technician in 1979, Nielsen oversees all automotive testing, repair and reviews for AAA. He has given testimony to the state and national legislatures, regularly provides guidance to industry groups and serves as an automotive expert to the national media.