- Dec 4, 2003
- Lansing, MI
First off, I did do some searching, seemed like several poeple have differing opinions on what turns oil black. The reason I ask is because someone made some comment like "I looked at the oil and it was so dirty that I immediatly had to swap it out" For some reason the use of 'dirty' in regards to someone looking at black oil is now one of my newest pet peaves. So what exactly causes oil to turn black? Is it mearly heat cycles? Does it really have anything to due with combustables being suspended in it? People made comments about dye, is the dye simply depleted somehow? So, if it has to due with heat... could I take a quart of oil, put it on my stove, carefully heat it up to operting temp for an hour or so a few times and have it turn black?