Not changing the oil is not just a female thing. Several years after my mother remarried (father is dead), I needed to borrow her car for a short trip. Before I hit the road, I did a quick inspection on it (fluids, tire pressure, etc.) and noticed that the oil was DARK BLACK and literally stuck to the dipstick (like caked on). So basically, the car was being lubricated by black sludge, about the thickness of well-mixed cement before it sets. This car was about 3 years old at the time. Judging by the sticker on the window, the oil hadn't been changed for over 15,000 miles. I asked her why the oil hadn't been changed. She said to ask the FIL (he takes care of such matters). So I asked him. Now this is a guy who does most of his own mechanical work, like changing trannies and stuff in his truck, so you would THINK that he would know better. But his explanation is that he had full synthetic oil put in the car, so it only needed to be changed (according to HIM, anyway) every 15,000 miles, and it was "just a little overdue" at the time that I had checked it.
I was quite honestly shocked that the car even started. But the gas mileage sucked rotten eggs. I would have had the oil changed while I was using the car, but I'd learned a long time ago that it wasn't smart to cross the FIL, as he had a hair-trigger temper and was well armed. Better to let it be. Not surprisingly, the car didn't last long. -Dave