Cumulative Synthetic Oil Discussion
Administrator
Joined: Jul 2002
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From: portland oregon
thats not exactly true. there have been some problems with CERTAIN synthetics when used even in the renesis because of deposits left over in the combustion chamber. because mazda doesnt want to take the time to test EVERY synthetic brand out there they simply say dont use any.
thats not exactly true. there have been some problems with CERTAIN synthetics when used even in the renesis because of deposits left over in the combustion chamber. because mazda doesnt want to take the time to test EVERY synthetic brand out there they simply say dont use any.
Registered User
Joined: Aug 2010
Posts: 125
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From: Milwaukee, WI
OK, I am going to ask 2 questions here:
1. Can you go back from synthetic to dyno on RX8? The reason I ask is I know the last owner of my car was using synthetic.
2. I went to 2 dealers in my area just to ask what oil to use, as soon as I said I have RX8 one said just use synthetic, I asked what brand they use on RX8 and he said Mobil1. The next dealer also said they are using Mobil1 Synthetic blend on RX8 oil changes. Also I went to few other locations for oil change, just to ask for type of oil I should use and all of them put the model in their computer and come back with "on RX8 you should use synthetic only"
What is going on here?
1. Can you go back from synthetic to dyno on RX8? The reason I ask is I know the last owner of my car was using synthetic.
2. I went to 2 dealers in my area just to ask what oil to use, as soon as I said I have RX8 one said just use synthetic, I asked what brand they use on RX8 and he said Mobil1. The next dealer also said they are using Mobil1 Synthetic blend on RX8 oil changes. Also I went to few other locations for oil change, just to ask for type of oil I should use and all of them put the model in their computer and come back with "on RX8 you should use synthetic only"
What is going on here?
Registered User
Joined: Aug 2010
Posts: 158
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From: Manvel, Tx
I'm curious as this to, based on the fact most synthetics are designed to resist burn off, it would seem only logical to use an non-syn oil that can be burned.
But I'm always open for clarification on the matter.
But I'm always open for clarification on the matter.
Guys theres a massive thread on this... Go look it up... If you have a question, chances are someone before you has asked the same question. This forum has been here for quite some time...
Registered
Joined: Dec 2006
Posts: 39
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From: Charlemont, MA
Okay, but nobody's forcing you to stay on this thread. If it's wasting your time, go elswewhere! I don't see how it's bothering anyone!
I highly doubt its just Synthetic oil causing problems. Im dare to say a lot of build ups are cause by people baby their car like its gonna blow up pass 3K rpm. especially the AT group.
im not saying ppl has AT drives like a grandma, but seriously will they always shift their car to Manual shift mode and redline it at least once a week. some like Jin probably would, but what about the rest of them? doubtful.
not to mention Mazda Japan's Synth-Renesis oil, hmm, I highly doubt its anything "special" when comparing it to other brand of Synthetic Oil. gotta love marketing.
Most important is : dont forget that all oil, mineral or synthetic, are constantly updating. So what killed Rotary years ago doesn't mean it will cause issue forever. Mazda messed up a lot too, like the cheap seals they used and now the clutch bracket, etc etc. does that mean Mazda suck? of course not.
im not saying ppl has AT drives like a grandma, but seriously will they always shift their car to Manual shift mode and redline it at least once a week. some like Jin probably would, but what about the rest of them? doubtful.
not to mention Mazda Japan's Synth-Renesis oil, hmm, I highly doubt its anything "special" when comparing it to other brand of Synthetic Oil. gotta love marketing.
Most important is : dont forget that all oil, mineral or synthetic, are constantly updating. So what killed Rotary years ago doesn't mean it will cause issue forever. Mazda messed up a lot too, like the cheap seals they used and now the clutch bracket, etc etc. does that mean Mazda suck? of course not.
I wonder what mazda uses as a factory fill oil? This had me thinking while I was comparing oils and premix in my garage this weekend. My Rotella 5W-40 was noticeably thicker cold (like 80F probably in the garage) than the the Mobil1 0W-40 I had on hand. Also, the Idemitsu I am using is a lot thinner and flows much better than the Kawasaki (Jaso FC) 2 stroke oil I was using as premix. Also, the Kawasaki premix and the Idemitsu do not mix at all.
Extraordinary Engineering
Joined: Oct 2005
Posts: 4,733
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From: Burls On
Okay, after reading this thread and several other articles I see no alignment.
Feel free to jump in... here are my thoughts.
BTW, I'm running the oil pressure bypass mod and AP with MMCCS. I'm not concerned about combustion properties of synthetic because I'm installing a Sohn adapter.
The car has been running 5W20 Castrol GTX until this summer. Now I'm running 5W30 Castrol GTX. Current mileage is 81K (131K km)
Since most engine wear is at startup I want an oil that flows freely at low temp but has good film strength and maintains 10cS+ at operating temp
Ambient Temperature range is 32F to 100F
So my thought is to run 0W30 or 5W30 synthetic from Redline.
Feel free to jump in... here are my thoughts.
BTW, I'm running the oil pressure bypass mod and AP with MMCCS. I'm not concerned about combustion properties of synthetic because I'm installing a Sohn adapter.
The car has been running 5W20 Castrol GTX until this summer. Now I'm running 5W30 Castrol GTX. Current mileage is 81K (131K km)
Since most engine wear is at startup I want an oil that flows freely at low temp but has good film strength and maintains 10cS+ at operating temp
Ambient Temperature range is 32F to 100F
So my thought is to run 0W30 or 5W30 synthetic from Redline.
Last edited by DarkBrew; Oct 12, 2010 at 06:58 PM.
Since you are in Canada, I applaud your choice of a lighter oil, but others will disagree, of course.
What I like about Redline 5W30 is that it has a HTHS spec that is similar to "regular" 20W50. So, you are getting the best of both worlds, it would seem - it should flow well (and therefore heat up quicker) when cool, and still protect well when run hot & heavy. The 0W30 does give up a bit in the HTHS spec, but flows a little better when cold.
Now, like everything else in this debate, *you* have to choose how much you care about HTHS vs. some other spec and/or additive, etc.
FWIW the engine tuner shop I use said that Redline breaks down quicker than Amsoil, which is what they recommend.
What I like about Redline 5W30 is that it has a HTHS spec that is similar to "regular" 20W50. So, you are getting the best of both worlds, it would seem - it should flow well (and therefore heat up quicker) when cool, and still protect well when run hot & heavy. The 0W30 does give up a bit in the HTHS spec, but flows a little better when cold.
Now, like everything else in this debate, *you* have to choose how much you care about HTHS vs. some other spec and/or additive, etc.
FWIW the engine tuner shop I use said that Redline breaks down quicker than Amsoil, which is what they recommend.
Extraordinary Engineering
Joined: Oct 2005
Posts: 4,733
Likes: 14
From: Burls On
Thanks for your response.
Getting real data to make a decision is difficult, even in this thread.
It seems to me that once the engine heats up the difference between the oil cS is very small so film strength matters most.
Also at temperature the oil is carrying away a lot (30 - 40%) of the heat but I don't know if there is a difference in this regard since all oil is thin at high temp.
I covered cold temp in the post above
The Amsoil vs. Redline issue... Is there any independent research anyone can cite that says one is better than another?
I found this a useful explanation of terms
http://www.acccc.net/index.php?optio...ance&Itemid=37
This was from general recommendations
Searching other car forums yields the exact same raging debate we have here....
Lots of opinion based on anecdotal information and conjecture.
The oil comparisons on-line all seem to be biased in favor of whatever company sponsors the "research"
Can anyone point to some unbiased measurement of actual performance?
Getting real data to make a decision is difficult, even in this thread.
It seems to me that once the engine heats up the difference between the oil cS is very small so film strength matters most.
Also at temperature the oil is carrying away a lot (30 - 40%) of the heat but I don't know if there is a difference in this regard since all oil is thin at high temp.
I covered cold temp in the post above
The Amsoil vs. Redline issue... Is there any independent research anyone can cite that says one is better than another?
I found this a useful explanation of terms
http://www.acccc.net/index.php?optio...ance&Itemid=37
This was from general recommendations
Originally Posted by Antique and Classic Car Club of Canada
the important thing is to use an oil with the same hot-viscosity rating as recommended by the manufacturer. That is, if your owner's manual called for a SAE 30 or a SAE 10W-30 oil, you can also safely use a 0W-30 or 5W-30. You will not get better protection with a higher viscosity oil like a 10W-40 or a 20W-50 unless your engine oil temperature is hot enough to reduce the heavier oil's viscosity to that of a 30-weight oil at normal engine oil temperatures (9.3 cSt to 12.5 cSt).
Wear is minimized in automotive engines when the engine oil viscosity is within its design range. An engine will wear faster when the oil is too thin or too thick so viscosity must therefore be in the right range for maximum engine life. Excessive viscosity also unnecessarily stresses oil pumps. Although most ACCCC members do not drive their collector vehicles in the winter, the low temperature flow capability of a 0W or 5W oil allows it to flow to the bearings faster than heavier weight oils at start-up. Using an excessively heavy oil will cause the safety relief valve to bypass oil back to sump at cold start-ups, thereby reducing oil flow to the bearings. Winter-driven daily driver vehicles would definitely benefit from low viscosity 0W/5W oils.
Wear is minimized in automotive engines when the engine oil viscosity is within its design range. An engine will wear faster when the oil is too thin or too thick so viscosity must therefore be in the right range for maximum engine life. Excessive viscosity also unnecessarily stresses oil pumps. Although most ACCCC members do not drive their collector vehicles in the winter, the low temperature flow capability of a 0W or 5W oil allows it to flow to the bearings faster than heavier weight oils at start-up. Using an excessively heavy oil will cause the safety relief valve to bypass oil back to sump at cold start-ups, thereby reducing oil flow to the bearings. Winter-driven daily driver vehicles would definitely benefit from low viscosity 0W/5W oils.
Lots of opinion based on anecdotal information and conjecture.
The oil comparisons on-line all seem to be biased in favor of whatever company sponsors the "research"
Can anyone point to some unbiased measurement of actual performance?
Last edited by DarkBrew; Oct 13, 2010 at 02:33 PM.
Now after a long decade of piston engines run on synthetic variations and teflon additives with no issues I find myself owning an 04 RX8 with a totally different version of the 13B. High compression.
My original owner's manual says: use SL rated 5-20W oil with no specification as to origin or color.
My engine is "new" having been replaced at 55k and only run for 4k with 59k now on the car. I don't know why it is new as I am the 3rd owner. I can only assume it failed the dealer/ factory authorized test procedure in 2009.
I bought 5W-20 SL rated Valvoline Dino to top it off. I figure I'll just do what the book says and keep it full of clean dino oil. Since I still have one year warrantee on the engine I'll treat myself to two Dealer oil changes this year and ask what they put in it each time?
Long ago I learned that the "blended" oil isn't some magical thing - they just pour 1 synthetic with 4 regular quarts. DOH. 20%. I can do that if need be.
I also learned you can mix different wts of oil with no issues. Two 10W-30 and two of 10W-40 it still works. Just don't mix brands due to the additives.
Once the warrantee is up next December I will have hopefully fallen into a routine of using whatever works for my FL climate and tons of autocrossing which I bought this car for. I bought it to flog it.
BUT I will stay with whatever brand/type/wt I am happy with at that time or have learned to be the most reliable by then.
One should never stop learning.
One should never be bored.
One should avoid being an ahole while on this board.
Super Moderator
Joined: Apr 2005
Posts: 10,880
Likes: 340
From: Australia
Jeez, the Renesis 1 in S1 RX-8's are NOT Totally Different to your 12A and more so the RX-7 13B.
There are More Engine parts common with the old 13B's and later Rx-7 13B's that there are unique RX-8 parts...in fact it has more commonality to a 13B RX-7 NA of 1985....Genuine Mazda PARTS FACT.
Just one example, the Stationery Gear Bearings used in the 2004-2006 Auto 4 Port RX-8 were the exact same ones used in the 10A and 12A and 13B used from 1969 to 1985...0820-10-502B.
There are More Engine parts common with the old 13B's and later Rx-7 13B's that there are unique RX-8 parts...in fact it has more commonality to a 13B RX-7 NA of 1985....Genuine Mazda PARTS FACT.
Just one example, the Stationery Gear Bearings used in the 2004-2006 Auto 4 Port RX-8 were the exact same ones used in the 10A and 12A and 13B used from 1969 to 1985...0820-10-502B.