If Dorothy oiled the Tin Man with synthetic oil, he probably wouldn’t have rusted on the way to The Emerald City. That’s because new research by AAA Automotive Engineering, on engine oil quality reports synthetic oil outperformed conventional oil by an average of nearly 50 percent. As a result, for only $5 more a month, synthetic offers vehicles significantly better engine protection than conventional oil. “Oil protects critical engine components from damage and AAA has found synthetic engine oils performed an average of 47 percent better than conventional oils in various industry-standard tests,” said John Paul, Senior Manager for Traffic Safety for AAA Northeast. Because synthetics have superior resistance to deterioration, AAA’s findings also indicate synthetics benefit newer vehicles with turbo-charge engines and vehicles that are frequently driven in stop-and-go traffic, tow heavy loads or operate in extreme temperatures.