Unlike some oil life sensors that perform chemical tests on the oil, the Oil Life System uses sophisticated decision-making software to determine when the oil's usefulness has ended. In actual driving, the Oil Life System has been found to double or triple the oil change interval for a typical vehicle. In its vehicles without the Oil Life System, GM currently recommends oil change intervals on two different schedules, depending on how the vehicle is being used. But in practice, most drivers do some combination of both styles of driving, so the guidelines are far from precise. In fact, because these guidelines are intentionally conservative, a lot of oil is being drained before its useful life has ended.
Oil changes are a significant environmental problem.
That's the equivalent of 20 supertanker accidents every year. Just one quart of improperly disposed used oil can contaminate 1 million gallons of water, enough to meet the needs of 50 people for a year. The Oil Life System grew out of GM's extensive Research and Development efforts, and it shows once again that GM is the industry leader in consumer-oriented technology and environmental protection. It employs about 372,000 people globally. GM also operates one of the largest and most successful financial services companies, GMAC, which offers automotive, mortgage and business financing and insurance services to customers worldwide.