timbit123

Hi guys, I'm new in this forum and I recently bought a rx8 2004,
i have a quick question, can i change oil to mineral oil if presently the car have synthetic oil. I know that synthetic is not really good because the oil isn't burning good.

my other question is how bad is synthetic oil, this car had never seen winter, it's only have 50 000km and the guy have 69 years old lol i don't think that he drove hard this car.

Thank you
Ps. sorry for my English I'm from Quebec hihi

rx8thunder

There is no issue with switching. As a matter of fact, get the synthetic oil out ASAP and put in non-synthetic. 5w20. Redline your car everytime you are out in it.

timbit123

redline... for what? cleaning the residue of oil in the engine?

shaunv74

Read up on some of the oil threads. There is a bunch of info. on this.

Synth is fine and changing it to regular is fine. But the popular thinking right now is 5w-20 is NOT fine. Most folks that have had their cars for a while have gone up to 5-30 or 5-40. The e-shaft bearing seems to need better film strength from a thicker oil.

timbit123

ok, otherwise what is recommended if 5w-20 isn't good?
And yeah, I still reading some threads on oil but... they are too many and not clearly

shaunv74

5-30 for your neck of the woods where it's colder in winter. Or 5-40.

timbit123

ah sorry my noob english, and I don't that i'll use my rx8 in winter,
thx

rx8thunder

Yes, to remove built up carbon on the inside of your engine.

In terms of the debate of 5w20 vs 5w30, who knows what the right answer is???? That debate will go on for centuries I suspect. Nobody has provided any definitive proof on which is best, it's all conjecture, so I will go with what the manufacturer suggests in Canada, which is 5w20.

shaunv74

From the Japanese owners manual for the RX8: Not conjecture.

http://www.mazda.co.jp/service/owner...x-8/70201.html

Note the diagram that specifies no less than 5-30 unless you go below -25C. North America is forcing car companies to move to thinner oil for emissions reasons. Not for the health of our engines.

Flashwing

80,000 miles of full synthetic and still going!

shazy

Eh salut Timbit! Bravo a finalement d'avoir un rx-8. L'huile de synthetique n'a pas de problemes, mais je ne veux pas risquer sa dans mon auto parce que Mazda a dite de ne pas utiliser.
Un chose tu as besoin de faire est de regarder le Section de FAQ pour avoir un bon description de cette vehicule. Dernier chose que je vais dire, Allez sur beaucoup de RPM! Remember, 1 redline a day (you have to go WOT and can be in any gear that you would like) keeps the redline AWAY!

REV-illusions

iTrader: (3)

I'll stick with 5w-20 thanks. If your engine craps on you and you don't follow the manufactures spec you should be **** out of luck. I've never had any problems with the 5w-20 and I drive my car year round. Why mess with something when you don't have to.

quazmosis

iTrader: (2)

I recently switched to 5W-30. I'm fairly close to Canada. I'm trusting the Rotary nuts on this forum that they are correct.

TheWulf

iTrader: (4)

https://www.rx8club.com/series-i-tech-garage-22/cumulative-synthetic-oil-discussion-52856/

Read it. All of it. I did and my end decision was to put the Sohn OMP adapter in and run 5w30 RP and Idemitsu Premix. Happy with my decision.

timbit123

thanks for all of you, what i said before, i'll not use my car in winter because the salt will destroy the car and I want to keep it longer. I also think that i will stay on 5w-20 because they recommend it and anyway i will not drive it under 0°C.

Shazy, lol for sure that i'll try that little engine, i want to hear it at hight rpm and the beautiful beep from the car when you have to shift

For quebec people, somebody know where i can find a shop for an exhaust?
And for all, witch model have the best sound for you?

carbonRX8

iTrader: (1)

jebuzz. This **** again. Can noone understand the concept of a search?


I will mention, at least one very experinced rotary mechanic uses 20W50.

But all y'all just keep drinking the koolaid MNAO is ladelling you.

Thumper3322

Do as thunder suggested!

Old man drivin can = not a good engine I would start working it in, as in slowly start driving harder and harder. And of course redline once a day.

millchan

I had a very bad experience on using synthetic oil. And just because I switched back to manufactures spec, my car runs smooth since it comes back from dealer. i wouldnt try and risk synthetic oil again. Although it is still a question about synthetic oil vs rotary engine...for those still using synthetic oil if your car still run fine or run even smoother, which is good for you. But bear in mind, what if the others engine find problem after switching synthetic oil and the dealer doesn't make a warranty cover because of the oil switch (coz on our user manual, the manual did say, "NO" synthetic oil). Would the one who suggest the others use synthetic oil cover the price for them? I would agree 5w-20 for a daily. Track RX8 with synthetic I don't think it is a really big issue, coz those 8 changes and clean oil every track day and even often.

For a daily, if you do want every 7000km change the motor oil, I would say 5w-20 is more secure and safe, stick to the manual. Factory default setting isn't come from nowhere, those are professional decisions.

https://www.rx8club.com/showthread.p...86#post3030686
check out this thread, you may find enough information to make up your mind. :-D

Welcome our proud new owner :-D

Ka Kui

iTrader: (7)

I only change my Rx-8 oil in Mazda Dealer, just stick with factory default, can't go wrong with it......... big debate on synthetic oil VS rotary engine, but don't risk it while you still have warranty on your 8's..........

Atilla

iTrader: (1)

Coming up on 50k on Royal Purple FULL-SYN and NO PROBLEMS.

Running with 10w-30 on an NA.

schnipster

why do we try and re invent the wheel, mazda,,,the people that make the motor say 5 w20....

Footman

iTrader: (2)

I run Castrol GTX 5W20 on regular top-ups in between oil changes. I change the oil every 4000km at the dealership. My car is daily driven 365 days a year. I seriously could not recall a day where I did not drive it! Sometimes when I have absolutely nothing to do and nowhere to go, I still go out for a spin anyways because it's so fun!

carbonRX8

iTrader: (1)

You know how to post, but you dont know how to read.


Does that help?

rotarygreg

I sort of agree with the whole "do as mazda says" thing. I mean, i have my reasons for and against it. Bascially, some mazda vehicles still do run/recommned 5W30. any vehicle with the MZR engine is recommended to run on 5w30. Also, the Bseries trucks (accept the b2300) are recommended to run on 5w30. So yes, the auto makers are being pressured to recommend lighter weight oils but they have freedom still. So that being said, they wont suggest something that will kill an engine that is still under warranty. also, with the wicked renesis warranty we all have now, they really wont be risking it with the oil wieght recommendation. If they feel the oil weight is inadequit and will cost them money in worn out engines, do you really think they would so haphazardly increase the warranty? No.

that being said, i have recently switched the oil that I use for the summer. I used to always run mazda 5w20 non syn. Now i've switched to something VERY heavy just to see how it goes. im running rotella t 15w40 non synthetic. The reason i switched is because in my opinion, 5w20 is way too thin once the weather gets warmer. It comes out of the engine like its water, even if the oil is cold, it still flows like water. We'll see what happens. likely nothing positive or negative. but it costs me next to nothing for this oil, so its a small price to pay for peace of mind when the temps get up there.

But to everyone that always runs 5w20. more power to you. trust in the maker. they wont put a wicked warranty on something that they have doomed to fail by their own doing.

Kafka

In Japan, they use 5W30.

In Speedsource Rx8, they used 5W20 in their race the whole time even though it is a Castrol Synethic sponsored race car...

There are numerous cases of synthetic engines still blowing up (most of them used car owner, so we don't know the history before they use synthetic), and engine rebuilder disassembling an engine for rebuild and found the 5W20 is lacking...

CONCLUSION: If you are still under warranty, I'd rather keeping the N.American spec. If you are out of warranty, do whatever that makes you happy!