The story first started around 30 something 40 years ago. to make it short, back then Synthetic Oil just "came out not very long ago", and Mazda used some cheap Rubber seals that does NOT work with "those" Full Synthetic oil back then. The result was The Synthetic Oil ate those seals alive and cost Mazda A LOT of money to replace them(cuz Mazda didnt say anything about them)

So after that, Mazda took the "better be safe than sorry" path and said "we do not recommend" Synthetic oil thinggy into their instruction.

Now we're in at the end of 2008 but Many many MANY people still living in the past, they simply refuse to accept the fact that technology DOES improve overtime, same thing for synthetic oil. not to mention it wasn't even Synthetic oil's fault. it was the cheap seal that Mazda used cause the problem. Those oil works with any other piston motor back then without issues. so whos fault was it really ?

What I find funny is that Mazda recommend 5w-20, at the same time they do not recommend Synthetic oil. But ALL 5w20 oil contains Synthetic oil inside them, so ... Did Mazda just slapped themself in da head again ?

u're in Chicago right? Not that far from NYC. I suggest you to use something like 5w-30, I personally use 10w-40. will switch to 5w-40 when Im back to NYC sometime next month. (Im on my vacation right now , far far far away from NYC)

he lives in Bangladesh, so yeah Im sure its gonna be "hot" over there

Oh hello my friend from Bangladesh, you will be fine using 5w-50 Mobil1 or 10w-40, I think you should use something like 20w50 for your area. it should not be hard to find 20w50.

 

Use a 10 or 15W40 or yes a 20w50 will be fine for Bangladesh.

 

It was my understanding that the JDM manual has no clause for synthetic oil. Also as has been stated, the manual states different oil weights for different climates, I am guessing a 10W40 would be the starting point for you.

 

GTX 5w20 is what you need, i live in soth florida 90+ and it runs perfect, no one knows what oil to run, so just get what mazda tell you to, you guys act like it will run better with Synthetic

 

5W-20 is too damn thin for a hot climate, you may get away with it but I will not risk a $30.000 dollar car on thin *** oils!

As a rotary owner since 1986 I have never run less than 20W-50 Castrol GTX in any roto motor. Both of my RX7's went well over 200,000 miles with 75 psi oil pressure at all times.

The fact that the EPA ****'s want 5W-20 for emissions and half of a percent MPG increase bothers me not one bit. I will run what is good for the engine, F@#K the 1-2 miles per gallon decrease.

 

teh EPA ****'s!?!1111 zomg.

 

well i know alot of peaple who has been in the rx family for a long time and they say 5w30 or 20 for florida, and i drive 8 hour days in it, starting and stoping for 100 miles,with out highways, i rev 5 time and gun the car alot and its perfect , i even take it to the track, i went thru tires 2 times last year

 

Could not agree more, we have to remember that the availability of oils in Bangladesh may be very limited in range, as the manual says and pointed out by many members here go with what your owners handbook says, it also points out that a 10 or 15W40 is acceptable for a hot climate. (Australian Handbook),so is a 20W50 or a W40 or W50.

I think the US manual says only a 5W-20, for the reasons you stated, emissions and MPG, that is all.

I will and would go for PROTECTION rather than the other two reasons.

The RENESIS can handle the thicker oils fine there are no differences in oil galleries for rotors or eccentric shaft of past 13B's, so you don't have to use a thin oil.
Yes the thinner oil is better for COLD start ups, but that is about all, I still do not think it has enough viscosity or protection when it is hot outside. There have been many examples of chewed out rotor bearings and damage to the eccentric shaft.
I can not confirm this is because of the 5w20 oils, however in the OLD days we only used 20W50 oils and very rarely witnessed ANY bearing or shaft damage.
In fact when I was a Mazda Parts Manager in the 70's, 80's and early 90's I could count on one hand the number of rotor bearings we sold at my Mazda Dealership, I never sold an eccentric shaft or new rotor, but hundreds of seal and gasket kits for the 10A,12A and 13B.

Please I am not suggesting the 5w20 is bad, I just don't like it, I would at least go for the 5w30 as a minimum.

 

Search Expo1's rebuild thread or Rotary Resurrection's rebuild thread. They both show the e-shaft bearings worn to the copper due to 5w-20 being too thin to provide the film strength needed to keep the bearing from rubbing on the race.

5W-20 is too thin.

 

and how many miles on you car? and what tires did you go thru ?

what track / tracks..

your advice is less than good.

beers

 

thx Nubo,spicez, nycgps,ash8,auzoom,freg and all of u friends now i m quite relife

by looking at these posts...... well its true its really hot in summer but now we

have winter going on, it wont be a problem if i use a fully synth oil right now i

guess bcoz hot season is about to come very soon.......well i will see how better i

can match up with these above suggestion and i will let u guys know what im

gonna use.......thx to all of u once again.

 

No one knows ? Just because Mazda didn't say it, doesnt mean that it won't work. Not to mention there is a chart in every single manual that tells you to use the "right" oil that matches ur local climate. I guess you missed that part.

That simply means you dont know anything about your motor in general. Please come back when you do.

I'll repeat this again, 20w50 is what you need for your local climate.

 

Using Mobile 1 5w20 Full Synthetic.

Honestly I am not sure.... I Don't notice enough changes to not just stick with synthetic blend?


Questions -- I live on Long Island (NY) -- would there be a different oil weight recommended for the summer / winter? Any difference -- To be honest I was thinking of using 5w30 In the summer and 5w20 in the winter.

 

Why don't you just use the 5W30, you are covered for both winter and summer, I still prefer a ?W40 weight for summer..

 

20W50, I agree, use that one

 

Anyone else here in NY use anything different now during the winter? It is 15 degrees outside....

 

still using rp 5w30 here in the city.. although I may go back to dino 5w30 come my next oil change.

 

I use ESSO Extra XD Synthetic, 0w40 here in Montreal.

Its -20c/-4f here right now. Works great plus I never get that slugish slow start at -40 I would get with 5w30 dino or synthetic. The 0w does make a difference in my case anyways.

 

ok i just picked up VR1 Racing Motor 20w50 & K&N oil filter, im going to put the oil in today, ill see how it runs, all im saying is, im just going to try it my self, i always left 5W20 in it, is this oil ok?

 

Ferg, the point is you do what you feel is right, I and others like me will do what we feel is fight.
I am running 10W-40 in the 8 now because I do like some fuel mileage and it is not a daily driver just my play toy.
Considering that the rotary world market spec is 5-30 or better, only the USA has a hardon for 5W-20 so I will go with a heavier weight oil.
Louisiana is a hot azz place!!!

 

yeah, but 20w50 for a everyday driving i think would help because i drive all day long, ill just try it, but its not going to burn faster? or slower

 

Your oil metering pump will still inject the same amount of oil so your oil consumption should stay about the same.

Keep in mind that a good portion of old oil remains behind in the oil coolers. After your first change from 5w20, your viscosity won't be nearly 20W50; it will take a couple of oil changes for that.

 

this whole subject gives me a headache... would i be ok with using 5w30 in Cali?

 

Prolly so but 10W-30 don't hurt either.

 

well i just walked away with a box of 5w30 mobil 1 synthetic with a mobil 1 filter.


first oil change, pray for me.