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Well since my last thread has been closed which I didn't know was an option, I am posting a new thread.
Went to Mazda for my oil change today and I usually do conventional (as per the manual 😁 ) stuck with 5w 30. As per my service manager I was getting what I requested. It was taking kind of long so I took a walk and saw my car in the bay. Went up to the guy working on it to see if he was almost done. Come to find out, they don't have conventional oil on hand. They put synth blend in it. Not that I wouldn't use synthetic, but was disappointed they weren't honest up front. Asked the mechanic if I should use synthetic or conventional when I need to add oil. He advised to put conventional in. They use Castrol. He claims he has requested to have conventional on hand for rotary's but it has fallen on deaf ears. I guess I won't be going back to Mazda. I'll buy the filter and take it somewhere else.
The question is has anyone one used or recommend synth blend? I don't think I've seen anyone on the forum who does.
I dont care for synthetic either but it will work just fine. Would recommend caution when posting an oil thread around here. The horse has long turned into a skeleton and any more beating it will turn to dust.
Last edited by CaymanRotary; 08-31-2020 at 05:19 PM.
I did so knowing I would probably get flack. Notice I did mention I have not yet seen a thread regarding synth blend hoping that would keep the wolves at bay. 🙄🙄🙄
From rotary revs in UK : the only people I've ever seen actually recommend them ...
Personally ...it's synthetic in my turbo and mineral in my N/A .... but I'm not stuck on that.
Rotary Revs recommends a 10w40 Semi-Synthetic engine oil of good branding for use in your rotary engine. Actually, we swear by Millers Trident particularly and you can find bottles of all sizes available for purchase in our online store.
The reason we recommend this slightly thicker rating (over the Mazda recommended 5w30), is to help protect you from stationary gear bearing failure. It is important to use a semi-synthetic oil rather than fully (synthetic) because semi-synthetics will burn reasonably cleanly and leave fewer carbon deposits behind in your engine; reducing the risk of apex seal obstruction which can lead to serious problems, resolvable only via an engine rebuild.
For me, conventional seems to be the safest bet. There is no doubting it will fully burn in the combustion chamber. Synthetic oils do have benefits though as they provide better lubrication. However, due to the frequent amount of oil changes, I doubt there is much added benefit to running a synthetic over dino. My opinion I suppose but I feel more comfortable using conventional. Castrol GTX 10W-40 for life.
Petscar, Excerpt from my previous post in your locked thread...
Changing Weight of Oil, post #11
"...End of day...for sure the manual s/b considered the base of knowledge, but to disregard the experience of owner / enthusiast's, some of whom m/b engineers, experience over the course of more than a decade and a half is...well...w/respect close-minded.
I dont care for synthetic either but it will work just fine. Would recommend caution when posting an oil thread around here. The horse has long turned into a skeleton and any more beating it will turn to dust.
We just resurrect zombie horses and beat them down again.
IIRC 5w20 MNAO recommended oil weight is a syn blend anyway.
I've personally used fully synthetic oil in Rotary engines for over 30 years, and not one of those engines has had any problems with the use of synthetic oils.
Synthetic oil will burn just about as well as any mineral oil and the big advantage of using Synthetic oils is it will last longer between oil changes and will keep your engine cleaner.
I believe that you run your engine at a disadvantage by using a mineral oil, even if you do regular oil changes, and I think this is prevalent with the Renesis engine due to the type of oil injectors that are used to lubricate the apex seals.
I'm in the process of trying to prove this to myself with actual physical proof, so far its looking like this is the case. Time will tell.
Now I will also say that not all Synthetic oils are equal, as some are much better then others.
Personally I'm not a fan of using lite weight oils in a Rotary, but thats my personal choice, most of the lite weight oils are designed for fuel economy which is not a strong point of the Rotary engine in the first place.
I feel that the Rotary engine is good in most cases using a 5 or 10w/40 and even better if used at high revs alot, then 10w/50 or something of the likes. Personally I use a 15W/50 in my turbo RX8 and a 5W/50 in my auto RX8.
Of course oil weights need to be considered carefully especially if you live in cold climates.
I saw a chart showing various oil weights. I don't remember what the parameters were in the chart but it may have had to do with temp/viscosity or other performance variable. But what really stuck out to me was the BIG difference going from 20 to 30 weight. 30 over 20 showed significantly higher by a factor of over 2 to 1. Whereas 40 weight over 30 was a much smaller increase. I would say maybe 1.2 to 1.
I was convinced going to 30 weight would be significantly better over 20 weight. Keeping in mind Mazda's recommendation of 20 w, I thought it would be a safer bet to go to 30w.
Since I take my car off for the winter and I do drive pretty hard, I may try 40w as quite a few of you are running it.
Thanks for all the good info. As some have said...oil is oil as long as you change it frequently. And since the question of synthetic or mineral oil will probably never be answered, I guess synth blend is a good option.
This is the exact thread i have been looking for. Being well aware of the dusty horse syndrome and also the fact that the strong wind has blown away all the dust. We now need a new horse!
All the major brands are doing syn/ dyno blends which are often half the cost of the pure dino oils where i live. Some of these advertise "part synth" or "synth blend". My question to any of you in the know is how much syth oil is in these? At half the price regularly to dino brand names it does make sense to possibly get onto these blends.
It would be good to have a facts page without opinions on these blended oils for every owner new and experienced alike to have options once they are informed.
I have literally spent hours searching for info about these blended oils..... ended up here after reading through many old threads. Some are closed which is fair enough as some people are *****. Note i am definitely not asking which brand or type is better! It would be helpful to know about what additives to avoid and which ones are harmless to our renesis engines. The engine oil analysis thread info goes right over my head. At least i am honest about it!
This is the exact thread i have been looking for. Being well aware of the dusty horse syndrome and also the fact that the strong wind has blown away all the dust. We now need a new horse!
All the major brands are doing syn/ dyno blends which are often half the cost of the pure dino oils where i live. Some of these advertise "part synth" or "synth blend". My question to any of you in the know is how much syth oil is in these? At half the price regularly to dino brand names it does make sense to possibly get onto these blends.
It would be good to have a facts page without opinions on these blended oils for every owner new and experienced alike to have options once they are informed.
I have literally spent hours searching for info about these blended oils..... ended up here after reading through many old threads. Some are closed which is fair enough as some people are *****. Note i am definitely not asking which brand or type is better! It would be helpful to know about what additives to avoid and which ones are harmless to our renesis engines. The engine oil analysis thread info goes right over my head. At least i am honest about it!
Get a Sohn if you can.
Idemitsu rotary oil is also a go
This is the exact thread i have been looking for. Being well aware of the dusty horse syndrome and also the fact that the strong wind has blown away all the dust. We now need a new horse!
All the major brands are doing syn/ dyno blends which are often half the cost of the pure dino oils where i live. Some of these advertise "part synth" or "synth blend". My question to any of you in the know is how much syth oil is in these? At half the price regularly to dino brand names it does make sense to possibly get onto these blends.
It would be good to have a facts page without opinions on these blended oils for every owner new and experienced alike to have options once they are informed.
I have literally spent hours searching for info about these blended oils..... ended up here after reading through many old threads. Some are closed which is fair enough as some people are *****. Note i am definitely not asking which brand or type is better! It would be helpful to know about what additives to avoid and which ones are harmless to our renesis engines. The engine oil analysis thread info goes right over my head. At least i am honest about it!
"Ah S*it, here we go again"
-GTA San Andraes
oil is oil. So long as there actually is oil in the car, your oil choice is up to you. Higher weights are recommended for hotter climates. 5w-20 is just fine in the winter months. I live in a tropical climate so I chose 10W-40 conventional. Its served all 5 RX-8's i know that are running it. Not one has an engine issue. May not be proof but it works for me.
Great response CaymanRotary. Also I'm not looking for any kind of debate whatsoever. I do have a lot of experience with older rotaries but limited with renesis. Never have i outlayed the extra $$ for synthetic on a rotary. It just so happens that some brandname blends are really cheap currently.
All the info around is as old as the dino oil itself, and everyone gets flamed for even raising any questions. Although i would never attempt to build a rotary of any age, i know a bit about them as i do search a lot and i like to get my hands dirty.
FWIW I am in the boat of oil is oil, change it regularly, dont buy the cheapest nor the most expensive, stick to brandnames and use the correct weight for your driving conditions. Considering this i am on the 10w40 and yes to the blended stuff. No bloody idea what other crap is these new oils nor its negative effects on our engines. Thats why i bothered to tap tap on my phone here.
I just love the 8 and all its quirks, I would definitely like my current engine build to last, and be armed with current info rather than good luck with all the old info on the lifeblood in our engines.
Did not get any love here. Im still looking for some specific info on the blends of oil. Also what additives to steer clear of. Not concerened or asking about brands or viscosity.
I have read tons of info both here and also our UK bothers and found myself doing a full circle on this stuff.
Of the two info packages attached, are either of these safe or even good for my freshly rebuilt resesis. I think they are but i want to hear from the guys with lots of renesis experience.
A specific question.... Is a zinc additive ok for a catless 8?? I can get this stuff ridiculously cheap atm. (The grey label).
I want to know if it worth stocking up on either of these synth blends?
You're question was never answered. One that I have been wondering about for a while and can't find an answer. The ratio of synth/dino blend? I'm sure it's different with each manufacturer. But at least a starting point.....50/50???
Thanks Petscar. I think after heaps of reading that often the synth blend is often very little. Hence low price! Some even say "synthetic technology". So probably none at all.
In short. Zinc good or bad? Other additives to steer clear of?
I’m following this hoping for more information along with you. I’ve read many of the oil threads which dissolve into distracting anger issues. Made a decision to change oil viscosity from x to y (my problem regarding choice and result) yet am still learning more and open to learning. New options lead to new questions.
Many of the issues regarding synth oil vs mineral are blurry, because the word "synthetic" has been rendered almost meaningless in the US due to labeling, lawsuits, etc.
What is encouraging for the rotary owner is the fact that DFI piston engines now are needing oils with better deposit control, which can mean better burning in a rotary chamber. Also due to LSPI in piston turbocharged engines. Maybe the better way to go about this in these times is to research some of the factory recommendations for their high performance DFI turbocharged engines, and see what criteria they are using for their licenses.
Modern engines are requiring oils to change fairly rapidly compared to the "days of old", and a lot has to do with deposit control and shearing due to timing chains, both of which will be helpful formulation changes for rotary engines, with their oil injection and rotor and stationary gears.
So, my advice is to forgo the synthetic/mineral search, and look instead at some of the modern oil requirements for piston engines, regardless of synthetic/mineral composition.
Last edited by kevink0000; 06-21-2021 at 06:34 AM.
I have an engine that i would be willing to use/sacrifice as a guniea pig for any oils in question. Except 0w16/20
I've been running 10w40 valvoline durablend semi synthetic on my "rebuilt" engine thus far approaching 10,000 miles. Later this week I will be sending a sample to blackstone for analysis.
Just switched to castrol 20w50 and will run this until august, at that point I'll try the ZR1 valvoline 20w50 with zinc.
Thanks kevin. Some wise words there. I have definitely read widely on ths and i know many dont bother to read, instead just ask the same old and tired questions. My original post here is now a mute point most likely.
No issues with blends or any others views on oil. It would just be great to hear about things like zinc and other additives and their known effects on our engines (if known).
Edited as i did repeat myself from prior post! 😉 Deleted text.
No additives in any oil, in any engine, please. Don't try to formulate your own oil. Find the oil you like and stick with it. Additives can cause more problems than they hope to solve.
I have a couple of over 400k mile piston gas engine cars/trucks that I have run for over 300k miles myself, (bought them used) that have excellent compression and wear numbers in oil analysis, and I have never used an additive in those engines, and I can safely assume the previous owners did not either.
08-31-2020, 03:57 PM
