RX8 Mazda Oil

Ndx

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I heard that Apex Seals don't like synthetic oils ... Because they need to burn it ... Thx
 
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Oklahoma
Use Mazda oil, using synthetic in a rotary is not recommended. If you wanted a good 5W/20 like GTX or Pennzoil YB instead of Mazda "brand" that would work too.
 
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I do wonder if Mazda has any problem using Group III synthetics in the rotaries? Or if they were just talking about PAO based oils?
 
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 Originally Posted By: Nickdfresh
I do wonder if Mazda has any problem using Group III synthetics in the rotaries? Or if they were just talking about PAO based oils?
I am not a raotary expert but I have heard of two issues and can think of a third. The first is that synthetics do not burn as easily as petroleum based oils and the Renesis engine injects oil into the combustion process. The second is that a film is left once the synthetics are inefficiently burned in the combustion process and that has a detrimental effect. The main issue for me would be the avoiding of my warranty and Mazda is not shy about doing that.
 
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If you are getting "carbon/gum" buildup, +1 on low ash (<0.9%) and I would also recommend low VII content which a 5w-20 would have and a real synth grp iv/v blend would/should have none. Gee why didnt they put in a tank you could fill with TWC3 outboard oil? These oils have ~1/2 the flash of conventional motor oils.
 
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I have had 3 RX7's. In street driven applications, regular dino low-ash 5w-20 or 5w-30 should be fine. You can even use the hydrocracked Motorcraft stuff if you'd like if you have the absolute need to use a synthetic. Otherwise, for racing applications and sustained high-rpm, you can use synthetic low-ash oils. Some feel that the 5w-20 was too thin for the RX-8 and had side seal and housing failures; using thick oils does not have any negative effects in a rotary, the "crankshaft" portion is partially gear-driven and does not like thin stuff, and you also won't see any horsepower/mileage losses in going to thicker stuff in a rotary, in general. In my street rotaries, I used a low-ash HDEO 15w-40 diesel oil. In the racecars, same stuff or Valvoline VR1 20w-50.
 
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 Originally Posted By: Ndx
I heard that Apex Seals don't like synthetic oils ... Because they need to burn it ... Thx
+1, as far as I know you have to use dino oil because of the engine design.
 
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Michigan
5w20 wow, I had to put 50w oil in my rx7s, I never liked the omp ((oil metering pump. regardess of what u decide upon, good insurance would be to dump 4 to 8 oz of high quality 2cycle in the gas.
 
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 Originally Posted By: o2man98
https://www.amsoil.com/dealer/techservicesbulletin/MotorOil/TSB%20MO-2007-09-06%20Mazda%20Rotary.pdf
I just finished reading it, seems like Amsoil's statement is a "we are innocent until proven guilty" defensive statement. If I were a rotary owner I won't feel comfortable trusting it. Now if Amsoil come out with a long term engine test with tear down, then they would earn my trust.
 
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San Antonio, TX
Is this "Mazda genuine oil"? http://www.suncopetroleum.com/5w30.html I was trying to apply Mazda rotary issues to all gasoline engines. I think Mazda genuine oil is Conoco/Motorcraft syn blend because I couldn't find any other info using key word searches. And I don't think the 5w-30 is a good grade for the rotary because in UOA it shears too much. On other designs deposits could go to ring packs.
 
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