Really? Then what color do you see when changed at 5,000 miles? Pink? Blue? Orange?
Maybe I didn't make myself clear in my posts, so let's try again...
Oil changes for 4runner: 10,000 miles
number of quarts in 4runner: ~6.5 quarts
type of oil recommended in the 4runner: 0W-20, which is either full or blended synthetic
Oil color at 5,000 miles, which is
HALF its recommended oil change: Between bottles 2 and 3 below, ie., a golden brown color:
I figured some of you might need some visual identifiers, so I grabbed an image online that might help you to determine what your oil should look like at 5,000 miles. Of course, this would mean that you would have to drain your oil and put it in a clear bottle to make sure its correctly colored. Rather than doing that, I've gone one step further and found yet another visual aid for determining whether your oil is colored properly:
As you can see, black oil is an indication for you to change oil. DARK golden brown (as opposed to a dark chocolate brown) means that your oil still has life in it and you can continue on for a while longer.
Do any of you know exactly why engine oil will change colors? Well, let me explain then!
There are three main reasons for oil changing color.
1. Oxidation: Engine oils have specific products added to them to create the specified oil's viscocity and cleaning particles, most notably, sulphur. The compounds oxidize from chemical processes within the engine.
2. Thermal Degradation: Exactly as it implies, high heat burns the chromophoric bodies in an oil, giving it a blackened color.
3. Contamination: Yet another self-explanatory reason for discoloration. Chemicals added to oils, especially antifreeze due to blown head gaskets, will cause oil to look more like milkshakes than oil.
Everyone has their own opinions on when to change their oil, and what the color of oil should be when they do so. There is not one solid answer that says it should be X color and X color only, or X amount of miles and X amount of mile only. The OP said a gasoline engine oil should be black at 5,000 miles (remember, this is HALF of the oil life for the 4runner), which I disagree with, as well as a whole lot of discussions online, many from oil companies and even Blackstone, a company that tests oil for a living.
So again I ask, at 5,000 miles, what color should the oil be? And at 10,000 miles, what color do you think it will be if you believe that at 5,000 miles, it should be anything else but a "golden brown color"?