AAA's 59-page report documents a range of industry-standard tests. The agency evaluated synthetic and conventional oil in eight tests that analyzed things like deposit formation, low-temperature performance and oxidation viscosity. AAA found synthetic oil protects critical engine parts 47 percent better on average than regular oil. With superior resistance to deterioration, synthetic oil should benefit newer cars, as well as those with turbocharged engines and anything driven in a lot of stop-and-go traffic, towing conditions or extreme temperatures.
A few cars require synthetic oil, but AAA says all cars can benefit from it. The agency found nearly half of all drivers don't know if synthetic oil is any better for their engine or think it isn't. Some think it's nothing more than upsell gimmickry, a factor that may boost already-high distrust in repair shops. Still, 45 percent of drivers use the stuff, according to AAA.
The difference in price is nothing to sneeze at. Oil changes cost $38 on average with regular oil and $70 with synthetic, AAA found. But if you change your own oil, you can recoup some of the difference. AAA found five quarts of synthetic oil averages $45 — only $17 more than the cheap stuff. Synthetic oil also resists breakdown better than conventional oil, so you may be able to drive farther between oil changes. (Check your car's owner's manual, as well as the labels on the oil itself, for specifics.)
"It's understandable that drivers may be skeptical of any service that is nearly twice the cost of the alternative," said John Nielsen, AAA's managing director of Automotive Engineering and Repair, in a statement. "While a manufacturer-approved conventional oil will not harm a vehicle's engine, the extra $30 per oil change could actually save money in the long run by protecting critical engine components over time."
