clem

The Castrol GTX 5w-20 that I use looks very transparent, like the color of a lager beer as I'm pouring it in. After draining it out at 3k mile intervals it's a fairly dark molasses-like hue. My 8's got 15k miles total, owned since Jan '04.

Wondering if I should start changing it at 2k, or is it normal for it for the oil to get this dark?

Hammer

It's normal. As the oil begins breaking down, it naturally gets darker. Molasses color isn't bad. If it gets real dark, almost black, you went too far between oil changes...

Brice-RX8

You also have to realize you are not changing all of the oil when you do an oil change for this car either. The 8 holds close to 7 quarts I think, most of which are in the coolers and lines. It is not easy if possible to drain it completely, so basically you are doing a partical change every 3k.

zoom44

your oil will look like that after 300 miles

crossbow

Oil color, smell, and taste are not indicative of its wear, or its remaining additive packages.

Only a UOA can determine how much of an oils additive packs are remaining, and how much containments exist.

http://www.blackstone-labs.com

Nubo

gasoline engines all have some amount of blow-by gases that escape the combustion chamber. This introduces carbon particulates into the oil. Some of these are small enough to get past any filter, and will color the oil. This happens quickly.

clem

Thanks for the replies. Sounds like 3k intervals will be okay then.

mmats69

Mines usually that color and a quart low. i drive a lot and checking it kind of slips my mind.

Tamas

iTrader: (1)

That's too often - but if it makes you sleep better...
I'd just go with the recommended intervals in the manual.

roonsrx

try using a purolator pure one filter, not the mazda junk. your oil will look cleaner! spend the money it is worth it

ZoomZoomH

iTrader: (1)

actually the mazda filter is very good, not junk :D

i'm actually switching back to mazda oem from pure one after i finish this batch of pure one's i have :D

crossbow

"Most" OEM filters are really good...OEM as in from the factory (not from the dealer).

If your curious about the construction, cut it up after use and post photos to the forum. Its probably a champion labs based filter.

ZoomZoomH

iTrader: (1)

just found out Advance Auto Parts have the PureOne's on sale for $4.95 this week, so I may end up sticking with PureOne's a bit longer after all :D

KYLiquid

since i add about 1qt ever 1k miles my oil tends to stay a golden brown untill I change it.