AtlBlkZ06

Hey guys,

I just changed the oil in my dad's GTO. The oil was black and pretty dirty. I'll take some pictures of the gallon with a backlight if necessary.

My question: Should I change the oil when it turns black/nasty? The oil was changed ~3k miles ago. The

Is black oil, bad oil?

Please, NO OPINIONS. I've read all these oil threads and, and I'm looking for proof that black oil does or does not contains contaminants.

Thanks all,
Ram

Z Fast

All oil contains contaminents. The question should be 'does the contaminents reduce the oils ablility to lubricate and protect the engine'. Unless there is something wrong with your engine, dark/black oil by itself is not a problem, nor deos it indicate there is a problem. My diesel is contaminated immeadiately with soot right after I change it, yet the oil is good for 10K miles.

If you want to know for sure, don't take our word for it. We know nothing about you engine and whether or not it is running properly. You want proof, just have the oil analyzed. This is the only way you will know for sure.

Tom

Gary2KC5

other than that just change it to your comfort level. some change @ 3k miles some 5k. Used oil is not going to look like new oil.

KeithKman

Was it Mobil1? M1 tends to get dark very fast. Do an oil analysis at 3k and if it comes back fine, change it at 5k miles and do another oil analysis. If it comes back good, change your oil at 8k.

allanlaw

Like the manual says, just wait for the oil life indicator to tell you to change it, or maybe wait until it reaches 15% or something like that, but at least once a year.

AtlBlkZ06

Thanks for the great replies.

Yes, what I meant to ask was "Does the darkening of the oil affect its ability to protect". And yes its Mobile1. When I start typing up a thread, I forget everything I wanted to say

I have my blackstone labs cup right here to catch some for testing when I change the oil on the Z tomorrow

I only have 500 miles on it and the oil is black already (It should be M1).

I know some of you think changing the oil now is a waste, but I'm more concerned with the particulates in the oil. Also, I wanted the analysis sheet after 500 miles. I'll post it when I get it back.
I predict that they'll they'll find high amounts of metal and other particulates.

I also plan to change at 3k after this. It should be interesting to see how they compare.

I'll keep you guys posted, and any other input is welcome

-Ram

Maui

I change my Mobil1 every 2000 miles whether it needs it or not. Cheap insurance.

mousecatcher

I do. Yet I changed my oil at 500 miles anyway. Ram, you sound conflicted about frequent oil changes. What you need to do is track the car, then you have a reason.

SMFCPACFP

If you noticed the Mobil 1 oil container, you won't find a color chart to indicate the color of the oil at which time a change is needed. The change interval is a function of miles driven, and driving conditions. I change mine when the DIC gets to zero (anywhere from 6 to 10 thousand miles). A Mobil engineer once told me that 15,000 miles would be safe Mobil One change interval for a V-8 under normal driving conditions

To the guy who said that you should get the oil analyzed? Is that practical? How much does it cost, and how long would you be without the use of your car?

To the guy who said that he changes Mobil One every 2,000 miles, I want to thank you from the bottom of my heart, as a shareholder of Mobil Exxon. If you feel good about a change every 2,000 miles, think how how much better that you would feel if you changed with every gas fill up!

rws.1

send a a sample to blackstone labs... the will tell you how much longer it is still good and what already in it...

AtlBlkZ06

You're right I am unsure about when to change the oil because everyone seems to follow an opinion and I want some scientific reasoning.

I want to know that "With my driving, the oil accumulates XX amounts of XX at a certain mileage. With the given trend, I should ideally cange my oil after xxxx miles".

The best way I figure is to test the oil at 500 and find out if the change was necessary or not.

"Cheap insurance" is great thinking, but if I find evidence that the oil is well above requirements at 5k, between all of us, we can save a lot of money and time! Exxon-Mobil surely doesnt need any more money than it has!

I'm not comfortable with changing the oil because:

"Its black."
"I drove for 3k/5k/6k miles."
etc etc.

I am going to change the oil now, then at 3k (3.5k odo) and again at 3k(6.5k odo).

I think the engine will litter far slower after the 3k change. After 5k, the oil should be good for 5k+ miles.
We'll see!

Please note that I'm only talking about street driving. Tracking is a whole different beast.

I haven't said anything about the DIC because I'm looking to find data to support/disprove these "rule of thumb" approaches that frequently pop up in these oil threads.


PS: I FINALLY got the tag, tax etc etc done and I can drive my Z now

Supersubes

I have my oil analyzed by blackstone often, and the answer is always go 2-3K longer. Change it when you feel like it. If your changing it with only a few thousand miles you ARE wasting good oil, but in my mind who cares, like mentioned above it's peace of mind and cheap insurance.

06.Z51.MontRed.Vert

I switched over to an Amsoil oil filter for my last oil change after reading a lot of positive things about them. This is the FIRST time my oil doesnt look black after it was changed. I've got almost 3000 miles on it and it looks almost like it just came out of the bottle. I've always changed my oil at no more than 3000 mile intervals (using either Royal Purple, or Mobil 1 oil), and did the first changes at approx 750 miles and 1500 miles. My car has almost 19,000 miles on it (currently with a Paxton SC). Prior to the Amsoil filter I used on this oil change I was using either K&N, or Mobil 1 filters. From what I understand the Amsoil filter uses all synthetic media and filters better than the partial synthetics in the K&N or Mobil 1 filter.

I have no affiliation with Amsoil at all, and this was my first time using their products. I will only be using them from now on.

mousecatcher

there was a previous thread on this topic which convinced me, aside from tracking the car, just go with the oil life indicator. the days of 3000 mile oil changes are behind us. please also consider that the warranty only requires following the DIC indicator. that to me is a strong statement.

i have better things to do with my time than change oil.

Cobra4B

I change my oil every time I drive the car... I know it's costly and labor intensive, but it's cheap insurance for my baby. I'm an ignorant *** who won't understand that modern technology allows for greatly extended drain intervals






FWIW I run Amsoil 5w40 in the Z06 and a K&N filter. I go by the DIC or every 3 HPDEs which ever comes first.

In my truck I run Mobil 1 15,0000 mile oil and a mobil 1 extended drain filter. I change it per the GM DIC or every 10k just beacuse that's easy.

NORTY

Maybe. HUH? "Black" oil does contain contaminants. Whatever you do, don't take a tribologist's word for it.

Oh, if you are concerned about your oil, then have an oil analysis done. It's about $25 and the results are emailed back to you within 3 days or so. Your car will not be "out of commission" during this time, providing you take the sample during an oil change.

Carbotech Adam

please list part# for amsoil filter would like to try on next change.

06.Z51.MontRed.Vert

http://www.amsoil.com/scripts/runisa...msoiloaf:index

There are a few guys that are dealers for Amsoil on this website (supporting vendors). I would buy from them, and save a few bucks.

rAte

I was cross shopping a Porshe before I ordered my Z, thier OCI is 20,000 miles! I guess they are ok with Mobile 1 on extended intervals.

I will be using the the DIC and changing at 25% remaining. It worked fine on my C5.

-rAte

AtlBlkZ06

I'm an amsoil "preferred customer", I guess I'll give them a shot.

You can apply for free, and it looks like you get about 25% off!

Ram