Many modern cars use an oil-life monitoring system that calculates when an oil change is needed based on factors such as driving conditions and engine operation. That means someone who drives 2,000 miles a year shouldn't necessarily assume they can wait several years for an oil change simply because they haven't accumulated enough miles. Frequent short trips, heavy stop-and-go traffic, extreme temperatures, dusty environments, and towing can all put additional demands on your engine oil. Changing the Oil Too Often Vs. Too RarelyThe 3,000-mile oil change rule made sense in an era of different engine designs and lubricants. The Bottom LineIf you're wondering whether to change your oil based on miles or time, the answer is: both can matter.