Pennzoil 10w40 - 1,621mi - 04 Mazda RX-8 Rotary

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Slowly racking up the miles on the oil while monitoring wear and oil condition to determine the best interval for this freakin Rotary engine. Only 4 quarts drain out during an oil change. Total sump capacity is 7 quarts, so 3 quarts of old oil remain and instantly contaminate the new oil... it sucks, but what can you do? Thinking of just calling it quits @ 1,500 mile OCIs. My cost per 4 quart drain n fill = under $10 and takes 5 minutes. Seems like a no brainer since my goal is to try to keep this thing spinning happily for as long as possible. Thoughts?
Code
OIL             Pennzoil yellow bottle 10w40      
MILES IN USE    1,621 miles          
MILES on unit   140,970
SAMPLE TAKEN    12/12/2018
Make up Oil     1qt

                         
ALUMINUM        2              
CHROMIUM        9                
IRON            14              
COPPER          1              
LEAD            3              
TIN             0              
MOLYBDENUM      127             
NICKEL          0              
MANGANESE       0              
SILVER          0              
TITANIUM        0              
POTASSIUM       2              
BORON           68              
SILICON         3                
SODIUM          25              
CALCIUM         1677           
MAGNESIUM       21             
PHOSPHORUS      575          
ZINC            683            
BARIUM          0               
 
                            
SUS VIS 210�F   63.5           
cSt @ 212�F     11.20           
FLASHPOINT �F   395            
Fuel %          <0.5           
Antifreeze       0.0             
WATER            0.0            
INSOLUBLES       0.1            
TBN                         
TAN            


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2,046
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Maybe try switching oils? Since you're using a 40-grade conventional (because wankel), what about trying a 15W-40 conventional HDEO? Something like Delo. Still cheap, comes in gallon jugs (handy for your 4 quart drain), and has far more antiwear additives.
 
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Man, don't see many of those on the road anymore, fun to drive. I'm guessing it's had a rebuild by now. What did Mazda call for a change interval? What killed alot of these cars were owners not staying on top of the typical rotary oil consumption.
 
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Originally Posted by 1JZ_E46
Maybe try switching oils? Since you're using a 40-grade conventional (because wankel), what about trying a 15W-40 conventional HDEO? Something like Delo. Still cheap, comes in gallon jugs (handy for your 4 quart drain), and has far more antiwear additives.
I plan on trying something else during the summer. I'm already stressing with the 10w40 during cold starts when winter shows it's true colors in Florida (30-40F in the morning), I can't imagine starting this thing with a 15w40 during winter. Haha. Factory spec for the US is 5w20. Coupled with natural fuel dilution from the ever rich running Rotary and I'm not surprised so many of these engines died early lives. There's just not enough lube to keep the apex seals from rubbing away.
 
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Originally Posted by Gasbuggy
Man, don't see many of those on the road anymore, fun to drive. I'm guessing it's had a rebuild by now. What did Mazda call for a change interval? What killed alot of these cars were owners not staying on top of the typical rotary oil consumption.
I'm not sure what the factory interval is. Never bothered to check but i'm sure it's 5-7,500 miles. No way I'd ever run it that long. This engine just isn't made to be economic. It's designed to give driving thrills unlike any other. Yea I barely see them as well and always turn heads when I'm driving it.
 
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Originally Posted by Artem
I plan on trying something else during the summer. I'm already stressing with the 10w40 during cold starts when winter shows it's true colors in Florida (30-40F in the morning), I can't imagine starting this thing with a 15w40 during winter. Haha. Factory spec for the US is 5w20. Coupled with natural fuel dilution from the ever rich running Rotary and I'm not surprised so many of these engines died early lives. There's just not enough lube to keep the apex seals from rubbing away.
Totally understand. I know they say synthetic is "bad bad bad" for rotaries, but is that really the case or just leftover wisdom from the early days of rotaries and synthetics? What about a 5W-40 synthetic blend or full syn?
 
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When I had mine, I had one with the Rotary Aviation kit that feeds the oil injectors straight TCW3 oil instead of engine oil. Went a long way toward reducing sump consumption and wear. I premixed TCW3 into the gas before then. Unless there is a good reason why not, I'd premix if I were you. Since you're doing very short OCIs, there is little fear of mechanical shearing. I'd run something like a 5w-40. Maybe a Euro oil instead of HDEO. I know life is rough for rotary catalysts. BTW, the worry for synthetic has always been that low quality synthetic leaves more deposits than conventional. This is not true of high grade synthetic, but everyone dodges the issue as much as possible.
 
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You want some consumption as to why I think the 13B only recommended dino oil for seals. Keep doing what you do. Just buy a Fram Ultra or M1 oil filter and change it every 15k. Nice car too.
 
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Originally Posted by 1JZ_E46
Totally understand. I know they say synthetic is "bad bad bad" for rotaries, but is that really the case or just leftover wisdom from the early days of rotaries and synthetics? What about a 5W-40 synthetic blend or full syn?
Those who run a stand-alone oil injection setup happily run synthetic oil, since it obviously protects better and can withstand the abuse better. The going belief is that since synthetic resists breakdown, and it needs to BURN in the combustion chamber, it will leave behind deposits and carbon will eventually ruin the engine, although the rest of it will be perfect. Lol. Since conventional is weaker, the idea is that it will burn off cleaner. I'd gladly run a separate oil injection tank but they are expensive and this isn't exactly a perfect example of an RX-8 to go all out and modify to perfection. It's a beater for me... although a nice and unique one at that. Plus I like experimenting with it. I think it should last a long time with such short OCIs. Clean oil is basically always being sprayed on the apex seals.
 
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Originally Posted by DoubleWasp
When I had mine, I had one with the Rotary Aviation kit that feeds the oil injectors straight TCW3 oil instead of engine oil. Went a long way toward reducing sump consumption and wear. I premixed TCW3 into the gas before then. Unless there is a good reason why not, I'd premix if I were you. Since you're doing very short OCIs, there is little fear of mechanical shearing. I'd run something like a 5w-40. Maybe a Euro oil instead of HDEO. I know life is rough for rotary catalysts. BTW, the worry for synthetic has always been that low quality synthetic leaves more deposits than conventional. This is not true of high grade synthetic, but everyone dodges the issue as much as possible.
Well said. I premix the fuel always with Idimitsu Rotary specific Lube. The series 1 RX-8 needs it the most, since it only has 2 oil injectors instead of 3 like it's suppose too. (Thanks Mazda) Many Rotary shops recommend splitting it down the middle and run a synth blend. I'd do that once my huge stash of conventional is used up by this beast. I got a ton of it on clearance just for the RX-8.
 
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Originally Posted by Marco620
You want some consumption as to why I think the 13B only recommended dino oil for seals. Keep doing what you do. Just buy a Fram Ultra or M1 oil filter and change it every 15k. Nice car too.
Currently using the OEM series one RX-8 specific oil filter. I kept the last one going for like 5-6k miles although the oil was changed like 7 times during that interval (600 mile OCIs) I agree with your idea though since that would make the most sense. No point in dumping a perfectly good oil filter.
 
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If you want to stick with conventional then I think your current regiment is fine. If anything the OCIs are a little too short. Perhaps run PYB 5W-30 in the winter and 10W-40 in the summer. Or another consideration is to run a conventional 10W-30 HDEO year round. Those are closer to a 40-weight than PYB 5W-30. HTHS is around 3.5... maybe a tad higher.
 
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Originally Posted by DoubleWasp
When I had mine, I had one with the Rotary Aviation kit that feeds the oil injectors straight TCW3 oil instead of engine oil. Went a long way toward reducing sump consumption and wear. I premixed TCW3 into the gas before then. Unless there is a good reason why not, I'd premix if I were you. Since you're doing very short OCIs, there is little fear of mechanical shearing. I'd run something like a 5w-40. Maybe a Euro oil instead of HDEO. I know life is rough for rotary catalysts. BTW, the worry for synthetic has always been that low quality synthetic leaves more deposits than conventional. This is not true of high grade synthetic, but everyone dodges the issue as much as possible.
I thought there reason for not using synthetic is because the rotary engine is supposed to burn oil by design and synthetic dosent burn as well?? Anyway I had An Rx7 back In the day. Long before the 8 and it was just too problematic although it could beat the mustangs and Camaros all day long.
 
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Originally Posted by 1JZ_E46
If you want to stick with conventional then I think your current regiment is fine. If anything the OCIs are a little too short. Perhaps run PYB 5W-30 in the winter and 10W-40 in the summer. Or another consideration is to run a conventional 10W-30 HDEO year round. Those are closer to a 40-weight than PYB 5W-30. HTHS is around 3.5... maybe a tad higher.
I agree that the OCIs are ridiculously short and I can probably run 2-3k with a stronger synthetic blend but for now, I'm fine with 1,500 mile spill n fill. Like I've stated, 3 quarts remain in the system during an oil change. Now if an OC was replacing say... 6.5qt of the 7qt capacity, that would be a different story.
 
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Originally Posted by Pinoak
I thought there reason for not using synthetic is because the rotary engine is supposed to burn oil by design and synthetic dosent burn as well?? Anyway I had An Rx7 back In the day. Long before the 8 and it was just too problematic although it could beat the mustangs and Camaros all day long.
That is the reason. Synthetic is stronger and resists burning, so it's not ideal as a 2 stroke oil that needs to burn off CLEANLY. I'm sure this is 2005 talk and today's SN spec oil are pretty much the same, regardless if it's conventional or synthetic. I'd rather not experiment with my engine.
 
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Who knows... maybe slight formula tweaks? Maybe Lab equipment variation? Maybe my RX-8 used up some calcium during the interval? Hahaha.
 
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400 PPM is not a lab variation. It's either just wrong, or indeed the calcium level has been lowered to the tier of a cheaper oil at a premium price.
 
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Originally Posted by Artem
Originally Posted by Pinoak
I thought there reason for not using synthetic is because the rotary engine is supposed to burn oil by design and synthetic dosent burn as well?? Anyway I had An Rx7 back In the day. Long before the 8 and it was just too problematic although it could beat the mustangs and Camaros all day long.
That is the reason. Synthetic is stronger and resists burning, so it's not ideal as a 2 stroke oil that needs to burn off CLEANLY. I'm sure this is 2005 talk and today's SN spec oil are pretty much the same, regardless if it's conventional or synthetic. I'd rather not experiment with my engine.
Not to mention today's blends are so close to synthetic it's almost a non issue.
 
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If your constraints are >3.5 HTHS of the blend, staying away from synthetic, and trying to get as much metallic FM additives, try Delvac XLE 10w30 (4qt) I think I've said this in another one of your threads, but, is it best to have organometallic FM additives, or ashless organic FMs?
 
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