do not use synthetic. it will leave lots of deposits unless you disable the OMP oil metering pump) and premix your fuel with 2 stroke oil.
Thats only true if you use a cheap synthetic.. Royal Purple is a good quality synthetic and especially in a highly modified turbo car such as mine.. its a better oil to use
Straight from the faq,
Originally Posted by IceMark
Can I use synthetic oils in my Rotary engined car?
Yes and no. Mazda offically does not recommend the use of synthetic oils in rotary engines, however, long term and racing use has shown that the better synthetics (Redline, Amsoil, Neo, Royal Purple, Mobil1) are perfectly fine to use in a rotary engine, and will generally result in a 1 to 2% horsepower gain. However use of poor quality synthetics (like Valvoline, Castrol Syntec, Havoline, Etc) will result in build up due to high ash content left from these oils when they are burned. It is believed that is why Mazda did not recommend synthetics, because the couldn't pick favorites.
The Mazda Factory racing departments recommend and use ‘synthetic’ oils including the winning 1991 Leman’s 20-G 4 rotor Mazda 787B.
MazdaComp USA printed manual (now Mazdaspeed) recommends the use of synthetic oils for racing conditions.
Redline, Amsoil and Royal Purple Synthetic Motor Oils have been used in rotary engines (both race and street) for ten plus years with excellent results.
Most Synthtic Motor Oil is compatible with the bearing material, sealing elastomers, and combustion seals used in a rotary engine.
What oil should I use in the FC?
According to Mazda:
In starting and operating temperatures below 20F, use 5W30
In starting and operating temperatures between 0F and 80F, use 10W30.
In starting and operating temperatures above 30F, use 20W50
As far as brand any good quality oil that meets the API SL or SM standards should be fine.
i would just stick with 20-50 castrol, personally. ive used it in my rx7 for a year now and it runs better then the day i got it by far.
dont just dump 2 stroke oil in your gas tank. you have to measure it out to a certain ratio. the 13b has a stock oil injection system that injects oil into the combustion chamber to help lubricate the internals while under combustion. over time this system weakens or dies which can be destructive to your engine. i am under the assumption that mine is dead so im adding 4 oz of 2 cycle oil to a full tank of gas to ensure it is getting some form of oil injection. instead of oil entering through the OMP injectors, it enters through the fuel injectors via your gasoline.
im sure that some synthetics burn just as clean as conventional oil, but im happy with using castrol gtx.
Have anyone tried quaker state? i got no OMP and im gonna change oil once a month (since there are trackdays pretty often)...
Buying expensive brands is out of the question if im gonna change that often...
Changing oil often vs expensive brands... Any oppinions?
Castrol GTX, 10W30 winter and 20W50 summer on my Vert. 20W50 all year on my Turbo. Just make sure you change it every 3k or less dependig on how you drive. And Mazda's stock oil filters is hard to beat.
if using synthetic if u can get ELF go with ELF 10w50 (thickest oil elf sells) Elf is 100% synthetic oil unlike mobil and castrol etc..
if using conventional oil use Castrol 20w50
in the states synthetic oil only has to have 5-8% grade 3 (grade 3 being synthetic oil) to be considered synthetic oil. ELF being made over in europe has a higher valuue and must be a minimum of 100% grade 3 however the elf 10w50 is a full grade 4 synthetic
and I always use a Nippon oil filter (nippon is the manufacture for mazda)
thats because of the fact that us spec synthetic oils are very ashy and alot of them will not burn correctly (for those using the stock omp)
Now with ELF oil which was only a european based oil untill recently they have a WRITTEN confirmation in the elf manual (I have many copies) that the ELF SRX oil will now completly comply and exceed any recomendations for the rotary engine.
thus why I am using the ELF 10w50 and as of now I have no ill effects form it .. it will leave alot less ash then mineral based oils, it burns better and more complete then mineral based oils..
HOWEVER I still stand behind the fact that any quality brand mineral oil will always do the job.. I just think for an extra 2.00 a qt (sometimes less) synthetic is the way to go
Well you guys are using the all expensive i have actually used stp I know it seems cheap but it is at every autozone and it works I have used it on my civic, my 77 dodge, and now i'm going to use it on my rx7 but you guys have talked me into it I want the mineral oil but i'm going to go get castrol gtx 20W 50 and where would you get aftermarket omp.
I change oil for a living. (Snappy Lube) an have a 87 N/A RX7. Unless your engine is boosted and you have an expensive after market turbo, run CASTROL or VALVOLINE 10/30
year round, chance every 2500 miles and go to MAZDA dealership and buy a MAZDA filter.