RX8 Mazda Oil

Ndx

Thread starter
Joined
Apr 4, 2008
Messages
1,878
Location
IL
I heard that Apex Seals don't like synthetic oils ... Because they need to burn it ... Thx
 
Joined
Feb 27, 2009
Messages
41
Location
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.
 
Joined
Mar 15, 2006
Messages
6,156
Location
Buffalo, NY
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?
 
Last edited:
Joined
Feb 27, 2009
Messages
41
Location
Oklahoma
 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.
 
Joined
May 17, 2009
Messages
16,903
Location
N.H, U.S.A.
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.
 
Last edited:
Joined
Jul 6, 2004
Messages
1,385
Location
Houston, TX
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.
 
Joined
Aug 21, 2008
Messages
25,051
Location
ON, Canada eh?
 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.
 
Joined
Jan 8, 2006
Messages
2,802
Location
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.
 
Joined
Aug 5, 2002
Messages
19,001
Location
Silicon Valley
 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.
 
Joined
Jul 4, 2003
Messages
3,118
Location
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.
 
Top