Make mine just a half an oil change please
#27
Registered
Originally Posted by shocar
Please refer to the Mazda RX-8 Shop Manual, Section 3 - Engine Specifications, Pages 31 - 32 Engine Oil Replacement:
Oil Capacity (Total Dry Engine) = 7.1 qt.
When the oil is drained for an oil change, the nominal amount of oil drained out is 3.7 qt. Approximately 3.4 qt. of oil does not drain out.
Approximately 1.0 qt. remains in each of two oil coolers. Approximately 1.4 qt remains within the engine itself. In my opinion, this oil pools inside the stationary rotors, at the bottom, in the cavity where the stationary gear meshes with the rotary gear.
Oil Capacity (Total Dry Engine) = 7.1 qt.
When the oil is drained for an oil change, the nominal amount of oil drained out is 3.7 qt. Approximately 3.4 qt. of oil does not drain out.
Approximately 1.0 qt. remains in each of two oil coolers. Approximately 1.4 qt remains within the engine itself. In my opinion, this oil pools inside the stationary rotors, at the bottom, in the cavity where the stationary gear meshes with the rotary gear.
You originally wrote
My point here is that the Owners Manual for both cars reads the same as far as oil change requirements. Say your RX-8 is off warranty but you have a sludged up engine even after following the recommended oil change practice. Would you get help from Mazda? I don't think so.
The oil that isn't drained doesn't just sit there in some corner and stay dirty - it gets circulated and mixed with the new oil, starting immediately the first time you run the engine after an oil change. Further, colour of oil is absolutely NO indication of the protection being offered by that oil. Unless you're having oil analysis performed on samples of your oil at regular intervals, there is no way to observe how 'good' your oil is. Again, colour is NO indication, and that has been proven many times over. In fact, oil analysis results are indicating that oil with a couple of thousand miles on it protects BETTER than new oil, so black oil can actually be better than that golden clear stuff! Even further, Mazda's specified oil change intervals for the RX-8 are much shorter than oil change intervals for most European cars - even if you only change half the volume at each oil change, you're still changing it twice as often as on European cars like BMW, Audi, and Mercedes - so how is this a problem, when the % of oil changed vs. distance over the long term is the same?
Going back to the original postulation, with a twist:
Say your Miata is off warranty but you have a sludged up engine even after following the recommended oil change practice. Would you get help from Mazda? I don't think so.
Regards,
Gordon
Last edited by Gord96BRG; 04-13-2005 at 04:58 PM.
#29
Banned
iTrader: (3)
Originally Posted by Gord96BRG
On an 04 RX-8, you should NOT expect to drain nearly all the total oil capacity for an oil change. They are different, BY MAZDA DESIGN.
The "design" allows for the engine to survive until the end of the warranty. After that, even a 50% faliure rate would be acceptable.
I still don't understand why this is an argument. Change your oil every 2000 miles. It wont hurt, it might help and it is cheap.
#30
Felix the Wankel!
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Originally Posted by Gord96BRG
....In fact, oil analysis results are indicating that oil with a couple of thousand miles on it protects BETTER than new oil, so black oil can actually be better than that golden clear stuff!...
![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
#31
My only point is that maybe the engine oil should be changed more frequently than what is specified in the Owner's Manual. This would be for the good of the engine and the people who own these cars. The RX-7 Website seems to contain similar recommendations.
There is, in my opinion, more learning on other similar topics that RX-8 people will experience over time that will bring RX-8 maintenance more in line with what is commonly practiced with the RX-7.
For the record, I will change my engine oil between 2000 and 3000 miles. And yes, I know that the huge majority could care less about that.
Gord is correct, many on the BITOG site think that egine wear increases immediately after a fresh oil change. The wear then settles down. But I've asked about this over there (the partial oil change aspect). I did not get much of a response. I know some people will think that is because this is such a ridiculous topic. I would have expected some people over there to recommended the use of Lube Control as part of the oil change as a means of restoring some desired properties to the used portion of the remaining oil.
I don't think that a mix of old and new oil is any kind of planned optimization of the lubrication design done by Mazda. I know people will disagree with this.
Having two oil coolers for the high power engine is to enable more satisfactory performance
when using 5W20 oil. The lower power engine has one oil cooler for similar reasons. The European cars have one oil cooler for similar reasons, that being the recommended use of 5W30 oil.
But it appears that a cat fight of some sort is going on with with this topic. So it is ok with me if this topic gets closed or even deleted by the administrators.
There is, in my opinion, more learning on other similar topics that RX-8 people will experience over time that will bring RX-8 maintenance more in line with what is commonly practiced with the RX-7.
For the record, I will change my engine oil between 2000 and 3000 miles. And yes, I know that the huge majority could care less about that.
Gord is correct, many on the BITOG site think that egine wear increases immediately after a fresh oil change. The wear then settles down. But I've asked about this over there (the partial oil change aspect). I did not get much of a response. I know some people will think that is because this is such a ridiculous topic. I would have expected some people over there to recommended the use of Lube Control as part of the oil change as a means of restoring some desired properties to the used portion of the remaining oil.
I don't think that a mix of old and new oil is any kind of planned optimization of the lubrication design done by Mazda. I know people will disagree with this.
Having two oil coolers for the high power engine is to enable more satisfactory performance
when using 5W20 oil. The lower power engine has one oil cooler for similar reasons. The European cars have one oil cooler for similar reasons, that being the recommended use of 5W30 oil.
But it appears that a cat fight of some sort is going on with with this topic. So it is ok with me if this topic gets closed or even deleted by the administrators.
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