No, not another oil thread, I just have a quick question.
I just changed my oil and was adding that last little bit to bring the oil level to the middle of the sight glass, when by accident I used some dirty oil that I had put back into last years empty oil bottles

. I can't even remember what type of oil it was. It was fairly dark, but not too bad looking. Maybe as much as 4 oz. before I realized what was going on and stopped. For arguments sake, let's assume the worst and say it was lawnmower oil.
So now I have that nagging paranoia that I need to change the oil all over again. But it's only 4 oz, out of a bit more than a gallon. Then again, I don't want to be penny wise and pound foolish.
Am I worrying too much? At $8 per quart for the oil plus the hassle I really don't feel like changing it again. I thinking the new filter will take care of the small amount of added dirty oil.
Feeling like an idiot an looking for opinions.