If gasoline prices hit $4 per gallon as many economists predict, an estimated 65 percent of American car owners say they will dramatically change their driving behavior, according to a study commissioned by the Automotive Aftermarket Industry Association (AAIA).

"While a third of consumers claim they already changed their driving behavior by curtailing driving or maintaining their vehicle better when gas prices reached $3 a gallon, the real tipping point is $4 a gallon," said Kathleen Schmatz, AAIA president and CEO.

According to a survey conducted by Opinion Research Corporation for AAIA, 91 percent of drivers are driving less and 75 percent are maintaining their vehicle better because of rising gas prices. Other specific behavioral changes were carpooling (31 percent), purchasing more fuel efficient vehicles (30 percent) and making greater use of public transportation (24 percent).