best motor oil for mazda rotary?
- Thread starter mattyp747
- Start date
- Status
WOW! 1988? Your generation was the Motor Trend '86 Car of the Year. Haven't seen one of these in a while. I remember when the RX hit the market in the mid '70's. Coolest little car around! And it was little!... Really scooted!
I don't really have an answer for you about motor oil choice but, from what I recall from reading here at BITOG, rotory engines like just regular motor oil. Probable something along the lines of a 10W30 or 10W40, NO SYNTHETICS. Im not sure why! Others will chime in with more info.
I don't really have an answer for you about motor oil choice but, from what I recall from reading here at BITOG, rotory engines like just regular motor oil. Probable something along the lines of a 10W30 or 10W40, NO SYNTHETICS. Im not sure why! Others will chime in with more info.
JHZR2
Staff member
IIRC, the rotaries actually burn a greater content of their motor oil, on purpose, compared to other IC engines. SO likely, you want something along the application lines in the OM for your typical temperatures, in an API SM setup so that cat converter deactivation is minimized.
Also IIRC, some folks dope their gasoline with TC-W3 ashless 2-cyle motor oil to add lubricity.
JMH
Also IIRC, some folks dope their gasoline with TC-W3 ashless 2-cyle motor oil to add lubricity.
JMH
Last edited:
There's a lot of "information" about the rotary: some of it is undoubtedly correct, and some not.
The earlier rotaries did have a major issue with synthetics. Mazda does not recommend them. People use them in the Renesis with seemingly good results.
I'm assuming you've recently acquired this car and since it is pretty old and you're not indicating that it has a new engine, I'd just continue to do what the previous owner had been doing.
I own a 2007 RX8. It has < 5000 miles on it now.
I do premix 2 cycle oil with my gasoline using Amsoil Saber Pro 2-cycle full synthetic...400:1
I have decided to use Amsoil XL motor oil and I'm starting to use FP+. Rotaries are noted for major carbon buildup in the engine (check your tailpipe and you'll likely see more carbon that you've ever seen).
I will convert the car to a Sohn oil adapter in the near future in place of the OMP (oil metering pump, which injects oil into the combustion chamber under computer control).
Whether this is the best combination to keep it running its best and for the maximum miles will be proven over time.
One last thing...may not be applicable to yours. But I've read time and again that a redline a day keeps a new engine away. In other words, cleaning out the carbon builup by driving it hard is good for the Renesis (new rotary design starting in the RX8 in 2004).
The earlier rotaries did have a major issue with synthetics. Mazda does not recommend them. People use them in the Renesis with seemingly good results.
I'm assuming you've recently acquired this car and since it is pretty old and you're not indicating that it has a new engine, I'd just continue to do what the previous owner had been doing.
I own a 2007 RX8. It has < 5000 miles on it now.
I do premix 2 cycle oil with my gasoline using Amsoil Saber Pro 2-cycle full synthetic...400:1
I have decided to use Amsoil XL motor oil and I'm starting to use FP+. Rotaries are noted for major carbon buildup in the engine (check your tailpipe and you'll likely see more carbon that you've ever seen).
I will convert the car to a Sohn oil adapter in the near future in place of the OMP (oil metering pump, which injects oil into the combustion chamber under computer control).
Whether this is the best combination to keep it running its best and for the maximum miles will be proven over time.
One last thing...may not be applicable to yours. But I've read time and again that a redline a day keeps a new engine away. In other words, cleaning out the carbon builup by driving it hard is good for the Renesis (new rotary design starting in the RX8 in 2004).
JHZR2
Staff member
Very interesting... does the OMP on he later engines inject crankcase oil? I know HD trucks do this. Can you modify it with a small sump to inject 2-stroke oil?
Sorry to hijack the thread.
JMH
Sorry to hijack the thread.
JMH
Yes, it injects the regular motor oil that lubricates the engine.
I've not heard of a modification where someone has bypassed oil input to the OMP and supplied it with 2cycle, but I'm guessing that's not possible as I'm sure someone would've done it. Of course that is a guess (I'm not an expert yet).
The Sohn OMP adapter does allow this though. If I recall correctly, the installation does require oil lines which does call into question my "guess" above.
With the Sohn adapter, you have a separate oil supply, generally a container mounted under the hood, and from what I've read everyone using it does fill it with 2cycle of varying brands.
There is a guy on one of the RX8 sites who seems to be pretty darn knowledgable about lubricating the RX8 engine and he used the Sohn and Amsoil's Saber Pro. I do or will do what he does with a couple of exceptions.
(1) he uses Marvel Mystery Oil in his gasoline and FP+. I'm using the saber pro and FP+
(2) i've not seen him disclose his motor oil brand of choice, but I'm betting it's Redline. I'm using Amsoil XL now, and may use the yellow bottle Pennzoil or Pennzoil platinum in the future.
For now I'm giving the Amsoil a try mainly cause I'd bought it prior to asking questions here. It seems better than what the dealer had put in it.
I've not heard of a modification where someone has bypassed oil input to the OMP and supplied it with 2cycle, but I'm guessing that's not possible as I'm sure someone would've done it. Of course that is a guess (I'm not an expert yet).
The Sohn OMP adapter does allow this though. If I recall correctly, the installation does require oil lines which does call into question my "guess" above.
With the Sohn adapter, you have a separate oil supply, generally a container mounted under the hood, and from what I've read everyone using it does fill it with 2cycle of varying brands.
There is a guy on one of the RX8 sites who seems to be pretty darn knowledgable about lubricating the RX8 engine and he used the Sohn and Amsoil's Saber Pro. I do or will do what he does with a couple of exceptions.
(1) he uses Marvel Mystery Oil in his gasoline and FP+. I'm using the saber pro and FP+
(2) i've not seen him disclose his motor oil brand of choice, but I'm betting it's Redline. I'm using Amsoil XL now, and may use the yellow bottle Pennzoil or Pennzoil platinum in the future.
For now I'm giving the Amsoil a try mainly cause I'd bought it prior to asking questions here. It seems better than what the dealer had put in it.
Ok, I supplied a little of my own misinformation. From what I've just read, the Sohn OMP "Adapter" does allow the stock OMP to be supplied with an external source of oil.
So the computer control and associated algorithm provided by the PCM to the stock OMP will be in play, only an external supply of oil is provided.
Nice solution to the carbon buildup problem that plagues these engines.
I'm sure Mazda doesn't do this because the typical RX8 owner is put out just by having to check the oil...adding oil to 2 places of different variety, esp with one burning at a rate of 100:1 is probably more than the average owner is willing to put up with.
Unfortunate for us enthusiasts who want maximum performance with reliability and are willing to do what is required to get it.
So the computer control and associated algorithm provided by the PCM to the stock OMP will be in play, only an external supply of oil is provided.
Nice solution to the carbon buildup problem that plagues these engines.
I'm sure Mazda doesn't do this because the typical RX8 owner is put out just by having to check the oil...adding oil to 2 places of different variety, esp with one burning at a rate of 100:1 is probably more than the average owner is willing to put up with.
Unfortunate for us enthusiasts who want maximum performance with reliability and are willing to do what is required to get it.
Idemitsu makes a rotary engine racing full synthetic rotary engine oil (PAO & Esters)
http://www.idemitsu-usa.com/page_211.htm
Might give it a try.
http://www.idemitsu-usa.com/page_211.htm
Might give it a try.
Originally Posted By: badtlc
Idemitsu makes a rotary engine racing full synthetic rotary engine oil (PAO & Esters)
http://www.idemitsu-usa.com/page_211.htm
Might give it a try.
Thanks, I've heard of it. Some do use it. I've also heard that Mazda co-developed it.
As far as using synthetics in the modern rotaries (not sure how to define modern, but surely the one I have), I'm pretty sure that many are using it with success. Having said that, I don't know the long term benefits or problems with using it in the Renesis. Those that use it tend to be the type that run their cars pretty hard and they don't seem to put many miles on them.
Also, some RX8 high performance companies use it, and recommend it for extreme cases (racing etc). Others don't recommend it exclusively citing the obvious differences between a daily driver and a racing engine. Some recommend it exclusively, with much heavier weights (20w-50 for example) regardless of the cars application...racing vs. daily driver.
Many argue about it on the RX8 related sites.
My car being a daily driver, well sort of, will not have its engine torn down regularly so those differences between the racers and the daily drivers are applicable to me. And this is why I'm sticking with a majorly GRPIII oil like Amsoil XL, Pennzoil Platinum or the yellow bottle Pennzoil (is it 60% GRPIII). I'll be changing it at 3k miles regardles of what I use.
The long and short of it is Mazda doesn't not recommend using it. They don't prohibit it, it's just not recommended and they qualify their position with "synthetics are not recommended since Mazda has not done any long term studies where it has been used".
Having said all that, with GRPIII being considered synthetic, and the Mazda recommended weight of 5w-20, nearly all of which have some GRPIII in them...what exactly is Mazda recommending. No PAO?
They seem to be talking out of both sides of their mouths, perhaps looking for reasons to not warrant or limit the warranties of these engines.
They seem to be subject to a higher failure rate than the a typical gaosoline piston engine sold in most cars today, most of which appears to be due to apex seal failure (analogous to piston rings).
Ok, I'm finished blabbering.
Idemitsu makes a rotary engine racing full synthetic rotary engine oil (PAO & Esters)
http://www.idemitsu-usa.com/page_211.htm
Might give it a try.
Thanks, I've heard of it. Some do use it. I've also heard that Mazda co-developed it.
As far as using synthetics in the modern rotaries (not sure how to define modern, but surely the one I have), I'm pretty sure that many are using it with success. Having said that, I don't know the long term benefits or problems with using it in the Renesis. Those that use it tend to be the type that run their cars pretty hard and they don't seem to put many miles on them.
Also, some RX8 high performance companies use it, and recommend it for extreme cases (racing etc). Others don't recommend it exclusively citing the obvious differences between a daily driver and a racing engine. Some recommend it exclusively, with much heavier weights (20w-50 for example) regardless of the cars application...racing vs. daily driver.
Many argue about it on the RX8 related sites.
My car being a daily driver, well sort of, will not have its engine torn down regularly so those differences between the racers and the daily drivers are applicable to me. And this is why I'm sticking with a majorly GRPIII oil like Amsoil XL, Pennzoil Platinum or the yellow bottle Pennzoil (is it 60% GRPIII). I'll be changing it at 3k miles regardles of what I use.
The long and short of it is Mazda doesn't not recommend using it. They don't prohibit it, it's just not recommended and they qualify their position with "synthetics are not recommended since Mazda has not done any long term studies where it has been used".
Having said all that, with GRPIII being considered synthetic, and the Mazda recommended weight of 5w-20, nearly all of which have some GRPIII in them...what exactly is Mazda recommending. No PAO?
They seem to be talking out of both sides of their mouths, perhaps looking for reasons to not warrant or limit the warranties of these engines.
They seem to be subject to a higher failure rate than the a typical gaosoline piston engine sold in most cars today, most of which appears to be due to apex seal failure (analogous to piston rings).
Ok, I'm finished blabbering.
Originally Posted By: mattyp747
i own a mazda rx7 1988 S4, just wondering what people thought was the best oil to use?
Castrol GTX 10w40 or 20w50.
Owners manual allows for 20w50 above 16*F.
Owners manual allows for 10w40 above -9*F.
Owners manual says NOT to use 10w30 above 86*F.
In your climate, i'd stick with GTX 20w50 year-round.
i own a mazda rx7 1988 S4, just wondering what people thought was the best oil to use?
Castrol GTX 10w40 or 20w50.
Owners manual allows for 20w50 above 16*F.
Owners manual allows for 10w40 above -9*F.
Owners manual says NOT to use 10w30 above 86*F.
In your climate, i'd stick with GTX 20w50 year-round.
Hi,
Dan - I totally agree with your suggestions, so does Castrol!
Dan - I totally agree with your suggestions, so does Castrol!
http://www.rotaryengineillustrated.com/how-a-wankel-rotary-engine-works/index.php
What PCMO's do you guys think would burn the cleanest?
Something w/o moly and lower in zddp?
iirc, there was an old Mazda test and they determined that one synthetic lead to excessive wear (from ash deposits?). Instead of naming the brand they just said no to synthetics in general.
But Royal Purple says their oil is ok in rotaries. And there's Idemitsu...
Wasn't Mazdaspeed (rotary) oil was just rebottled Neo?
What PCMO's do you guys think would burn the cleanest?
Something w/o moly and lower in zddp?
iirc, there was an old Mazda test and they determined that one synthetic lead to excessive wear (from ash deposits?). Instead of naming the brand they just said no to synthetics in general.
But Royal Purple says their oil is ok in rotaries. And there's Idemitsu...
Wasn't Mazdaspeed (rotary) oil was just rebottled Neo?
The seemingly "weak" additive package of Valvoline dino seems to be a good thing for rotary. Less additive, less ash.
Idemitsu was designed to be able to use the stock oil injection. Their pre-mix was designed, at 1/2 oz per gallon, to supplement the stock OMP.
I use their oils (which are compatible for mixing weights) in a 3 rotor RX-8 race car, along with 1.5 oz per gallon of Idemitsu pre-mix (No OMP). I have found no down side to running either.
I use their oils (which are compatible for mixing weights) in a 3 rotor RX-8 race car, along with 1.5 oz per gallon of Idemitsu pre-mix (No OMP). I have found no down side to running either.
20b in an RX-8, sweet!
- Status
Similar threads
