yiksing

Ok what do you mean by 15w50 is too thick? My dealer uses 20w50 on mine, manual says 0w20. I did a bit of search on the Internet but I still don't get why higher viscosity is not better for the engine and I thought it was supposed to be good.

StealthTL

iTrader: (1)

Why would higher viscosity (thicker) oil be better? Why stop at 20w50, why not get "better" 75w90? That oil you're using will be only as thin as a 50 weight oil would be at operating temperature, probably a fine choice for a clapped-out 4 banger with high miles, but like glue in a modern tight tolerance engine.

The higher viscosity causes mechanical drag, slows oil circulation, heats the oil, slows fitering, and most importantly - removes less heat.

Rotaries do a high proportion of their cooling via the oil system, and anything that heats or slows circulation can only be a detriment.

The new specs for oils that "sound" too thin are actually quite good - people have been looking for increased wear with these oils, and it just hasn't happened. The 20w50s usually have high levels of pour point depressants to achieve the "spread" between 20 and 50, these metallic additives can build up and bridge the gap on spark plugs, and plug catalysts, if burned in quantity (as in a rotary) so again, a poor choice.

Are you sure your manual specifies "0w20"? I have never seen that requirement in a manual.....your car is probably J spec, and they have always specced 10w30, US models spec 5w20.

S

yiksing

My manual says 0w20 but my dealer uses 20w50 (its cheaper for them I guess coz they contracted Shell for supply, well Shell is the only petrol company in my country) or maybe the temperature in my country ranges from 24 - 38 celcius.

I'd thought higher viscosity was better from less oil breakdown to high heat when operating the engine hard but I guess I was wrong since lower viscosity makes less oil pressure thus better flow. My 8 only comes with single oil cooler and noone can fix a rotary here (yes not a single person) if **** happens so i'm a bit paranoid about engine care. On mazdatrix website, they did say they use 20w50 so i'm very lost as to what viscosity to use.

RotoRocket

iTrader: (1)

shud a wud a cud a...

zoom44

id think 20w50 would be perfctly fine for the normal temps seen in Brunei.

G8rboy

Exactly... a lot has to do with climate. I ran Mobil1 15W50 in my Miata in the summer when I lived in South Florida... otherwise the HLA clatter was intolerable.

brillo

jeez lighten up folks. If a post looks like it may be from someone who isn't fluent in English, cut them some slack.

Especially when they are asking about a oil that sounds foriegn to most folks, that should be a clue.

AND FOR THE LOVE OF GOD, THERE IS NOTHING WRONG WITH SYNTHETIC OIL FOR THE ROTARY ENGINE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Niaz

im from bangladesh da temp is pretty high......SAE 15w 50 synthetic oil shud be ok for my renisis....and watz da benifit of using regular 20w 50???i need sum opinion frndz...cuz im very much worried abt may engine,cuz itz my baby and i luv my rx-8...plz help me out...

yiksing

Although I'm using conventional oil, I would like to switch to synthetic very soon after I verify how clean they would burn in the combustion chamber.

nolarx8

what is with the search button. its like people chime in just to tell you too search. if you dont like the same ? asked more than once dont look. i kinda like hearing different views on subjects and i dont mind being asked the same ? asked more than twice

StealthTL

iTrader: (1)

Yes, I suppose Helix is the best choice if the whole country is owned by Shell! The Shellfare State.

I work with many guys from the LNG plants in Brunei Darrusalem, great friends!

Good luck with the '8....

S

mikefives

wow...you guys are hard ***'s...not sure if i should be on here asking for help.lol...RX-8 type S????also im looking for some aftermarket part any suggestions on good web sites or dealers{and yes i know there is a link for dealers on here,please dont climb up my *** about it}

CyberPitz

Type-S?
http://lmgtfy.com/?q=rx-8+type+s

As for aftermarket parts, go to the for sale section on this forum, we also have a vendor section.
https://www.rx8club.com/vendor-forums-60/

The rest, please follow the advice of everybody in this thread. SEARCH!

REDRX3RX8

Not only should 15w50 be ok, but it's better than 20w50 just as 0w50 is better than 15w50.

I spend several months a year in Indonesia, and noticed that many people use 20w50(the dealer always puts an oil tag reminder on the turn signal) in everything, and also 15w40 is popular.

The weather is simuliar across SE Asia (hot and Humid), and choices of oil are slim and expensive, and I see people driving their cars looking mint for 20years.

If you can afford 15w50 use it with confidence, but if you find 0w40 use that, but don't use 5w30.

5w30 was designed during the 80's lets use US people for a test bed to see if we can lower gas consumption without killing engines era.

REDRX3RX8

Stealth,

Actually 75w90 is close to 20w50.

The 90 in gear oils is about a straight SAE50, and the 75w is about a 40w -45w.

Of course, gear oils have all those reactive sulfur compounds for the extreme sliding of the hypoid gears, so that would be a no-no in a engine.

For all you guys needing a GL-4, or lessor sulfur additive for your manual trans, sometimes straight SAE 50 motor oil without many additives for suspending dirt can be used, however that recommendation is for some truck trans.

What baffles me is the ATF recommendation and use in lots of manual transmissions from some Chrysler to many new expensive sports cars.