Must share this, was talking to a friend the other day and asked about his 09 Mazda3 that he purchased new. Mostly highway miles. Car is now at 220k and he confessed oil was changed once in last 115k some where around 50-60k miles ago. Always checked the oil and just last month had to add 1 quart for the first time! Never used synthetic. His reasoning was he never thought it would last much passed 100k so why waste money on oil. Now he's afraid to change it. I know him he's not a [censored]'r