Oil Color

Odd thing about my new Subaru Imprezza - when changing the oil, within a couple hundred miles the golden color has changed to dark brown, if not black. Just in a couple hundred miles. The car has always burned/lost about a quart per 4 thousand miles. But I’ve never seen oil turn so dark in such a short period of time. The car has 16,000 miles on it currently.

Conversely, my Toyota Tacoma truck with 125,000 miles on it never changes oil color - you change it and 4000 miles later the oil is still near golden color.

Any ideas or comments? Should I assume that all is okay with the Subie, even though the oil goes black pretty fast?

Black oil in itself is no cause for worry; your oil will be black longer than light color before you change it. I agree, however that it should not turn black before 1000 miles or so. The cause is usually incomplete combustion, causing soot, or excessively high operating temperatures which carbonize the oil. I would have the injectors checked, if defective it could inject too much gas in one cylinder and the carbon could end up in the crankcase. Or, the computer could be malfunctioning and make the air/fuel mixture too rich. If the car is turbocharged, the very hot turbo bearing will turn the oil black quickly. The car is still under warranty, so the dealer must have some explanation as well. If the Impreza is only used for stop and go driving in cold weather, the oil will go black quickly as well.

Just a guess, but did you change oil brands or types? I would guess you got one with more detergent in it or someone said they changed the oil and did not.

Some cars just get the oil black sooner. I can’t get out of the driveway before mine is black, but I do drive a diesel.

Sometimes a car is designed for a different type of filter. GM products used to get discolored while Fords stayed like new. I don’t think it’s anything to be concerned about.

The only true way to tell is a Used Oil Analysis, however it likely shows the oil is fine.

Are you checking the oil first thing in the morning or 5 minutes or so after it ran? If the oil has settled over a long period you may find darker particulate attracted your dipstick.

There is always a difference between the color of the oil on the dipstick and the color of the drained oil. The oil can look fine on the dipstick and look black as night draining from the pan. The only oil I have ever seen drained clean-looking was when it was drained from a manual transmission, where there is no blow-by mixing fuel with oil.

So if you are concerned about the color of the oil as it drains, don’t worry about it. Don’t overthink your oil changes. If you are worried about the color of the oil on the dip stick, you might consider a more frequent oil change interval or a used oil analysis.