No, they don't. But on the other hand, an oil changing its color does
not necessarily mean that it must be replaced.
And as far as the OCI, time is a factor, too, not just miles, so the OP
needs to take this into account.
The dark color of the oil is by no means an indicator of it's ability
to provide protection for the engine. Some oils turn dark very
For the record the main reason oil needs to be changed is mainly that
the additives are used up. The filter cleans out all(most) of the grit
but the oil itself is unchanged, as far as a lubricant.
The surfactants and anti oxidizers and corrosive inhibiters have been
used up. There are some who believe we should only replace the
additive package at prescribed intervals and leave the oil in the
engine. That's why it gets recycled. To clean and reformulate it with
new additives and then sell it back to us.
Follow the makers recommendations as to the correct oil for that car
and you should be OK regardless of the appearance of the oil.
You'll find that the engine for this car requires fully synthetic and the
BMW service interval is 15,000 miles. I've had my 330 since new four years
ago, done 60,000 miles, serviced it every 15,000 miles at the dealers and
guess what? - no problems!
You really didn't need to change the oil then either. Your car would be
running just fine with no more problems than you've had if you had left
the original oil that came in the crankcase. You'd have saved 4 oil
People reading/posting in this thread may not be aware that Fred has
been arguing for more frequent changes in the "E39 Change Oil Myself?"
In any case, engine problems due to oil sludge buildup generally show up
in an engine's lifetime than 60K miles.
The colour of the oil is not a reliable indicator as to whether it
should be changed.
Do you really want to know how far you can go between oil changes? Get
a used oil analysis done at a lab like Blackstone Laboratories (no
affiliation, just a happy customer). They'll send you a free collection
kit in the mail. They will use a plasma spectrometer and what's known
as total base number analysis to determine scientifically how much life
there is left in the oil you send them.
After an experiment or two, you'll find out scientifically how far you
can go, and avoid the religious wars in automotive discussion groups
like this one.
bobistheoilguy.com is a great site you should check out.
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