Automotive Research

AAA engine oil study shows synthetic oil performs better than conventional

An unscrewed engine oil cap

A new AAA study shows that synthetic oil performs nearly 50% better than conventional oil.

However, few vehicles require synthetic oil. In most cases, drivers can choose between conventional or synthetic oil that meets their vehicle’s specifications. Regardless of the type of oil used, car owners should follow their vehicle manufacturer’s recommended oil change schedule.

The study further concluded that:


Use conventional
engine oil


Use synthetic
engine oil


Don't know
type used

About 45% of U.S. drivers are either not sure whether synthetic motor oil is better for their engine, or do not believe that synthetic motor oil is better for their engine.

Skepticism toward synthetic oil may stem from American distrust in repair facilities. A separate AAA survey found that two-thirds of U.S. drivers do not trust repair facilities, with most respondents concerned about receiving recommendations for unnecessary services.

Drivers looking for a reliable repair facility should consider one that is part of the AAA Approved Repair network. These facilities meet AAA’s high standards including technician certifications, insurance requirements, rigorous inspections, and customer satisfaction.

Find a AAA Approved Repair facility.

Which is better?

Two plastic containers of oil being poured out

AAA's findings indicate that synthetic oil is beneficial to newer vehicles with turbo-charged engines, and for vehicles that frequently drive in stop-and-go traffic, tow heavy loads, or operate in extreme weather. 

It also revealed that the average cost of a conventional oil change is $38, while a synthetic oil change is $70.

For those who change their vehicle’s oil themselves, the average cost for 5 quarts of conventional oil is $28, while synthetic oil is $45.

AAA engine oil study takeaways

  • On average, synthetic oils outperformed conventional oils in the conducted tests by 47%. However, few vehicles specifically require synthetic oil.
  • Motorists should consult their owner’s manual to determine the required oil specifications for their vehicle, and select oil that meets those specifications.
  • Drivers who frequently experience stop-and-go driving, tow trailers, or operate in extreme hot or cold climates should consider using synthetic engine oil as it may provide additional protection for the engine.
  • For those concerned about long-term engine reliability, synthetic engine oil could result in less wear over the life of the vehicle.
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