Most of Castrol's GTX line of dino oil come in a white bottle.

 

What he said. I thought North America was the only market where the manual says 5W20, and in every other market it says 10W30.
I highly doubt Mazda has North America seals, and "Everywhere else" seals.

 

this is for #84 racing guy on here...first of all do some research before u post that the RX8 was designed for 5w20 lol.......do search and research then post before u say the wrong thing.....Everywhere else in the world they use 5w30 except Us and Canada they use 5w20 do to regulations.......so we burn less fueal which is only a precentage works out for the whole fleet of cars mazda has...why do u think we had so many egine failures in U.S. and Canada??? The oil is too thin


and as for warranty mazda cannot deny it if u use 5w30 ...and the difference is so minimal they would have to use the forensic team to prove it

 

I am not taking sides in this but....first off......you will need to do your own oil changes to put in 5w30 oil.....and then when your engine fails ( related or not related to the oil you have put in ) Mazda will ask to see your proof of maintenence and when you show them that you have used 5w30 they could immediatley deny your warranty, and you will be fighting for a while to get them to agree to anything. If any rx8 owner have learned anything. its that mazda is not very helpful when it comes to honouring warranty with the rx8...its like pulling nails. I agree that 5w20 is a little on the thin side, but it keeps the warranty valid. I personally think that 5w30 will remove less heat from your engine than 5w20 and that could contribute to premature wear due to excess heat. I haven't heard anything about specific north American designs for seals in conjunction with 5w20....from what I have heard its more for emissions puposes. But XXXrx8XXX before you go reamimg out a member you should look at what you last posted " the difference is so minimal they would need a forensic team to prove it ". We know that 5w20 cools the engine better, maybe it doesn't lubricate seals as well but like you said the difference is minimal at best, and I haven't done a lot of reasearch on the topic but I haven't seen anything that directly realtes engine failure to using 5w20 as opposed to 5w30. I have seen people speculate but never prove anything. Also, as someone who has just started to use 5w30...have you concluded any reaserch of your own besides what you feel your car runs like?? or are you going on what every one else has said? Have you driven any other rx8's who have used 5w20 and then seen the difference in their car after using 5w30.....I can tell you that their was absolutely no difference in my idle quality...although my car has never had an idling issue. My point is, its your car so do whatever you want, but on the off chance your engine fails and mazda comes on this board and sees that you have posted using 5w30 and then voids your warranty don't be shocked, they have voided warranties for a lot less.....and when you consider the oil is the life blood of the engine, messing with that gives them more than enough grounds to void your warranty. Just my 2 cents.....but maybe a little more respect towards a member I would hesitate a guess knows more than you about this engine would be advised, even if the statement he made wasn't accurate. The 2 posts prior to yours weren't rude, just stating their own opinion, why couldn't you do the same without the negativity?

 

its not that i am rude maybe it just sounds like it in my post. LOL but as long as you keep ur receipts for the oil filter from Mazda that i buy, then they have no right to void waranty. Yes and i know they are a.....holes at the dealerships but thats just life one denies go to the next same with pcm reflashes....

and honeslty i never had ideling problems either i actually change my oil every 2000km used 5w20 oil but just noticed that using 5w30 my fan does not come on so hey it works for me

 

engine failures has more to do with rate of oil injection and OMP readings than type of oil. Also the rotary is prone to carbon built-up. So most engine failures were automatic and 2004 cars where cars hardly see the redline to blow out the carbon. There has no proven correlation about type of oil that causes engine failures. Hot climates like Vegas and Florida will benefit from thicker oil. Where I am in BC, the weather is mild and most of the time err towards cold. So 5w20 has been good for the car. In fact there are likely more stock rx-8 on the road using 5w20 than the entire forum members put together.
In the end, use whichever you feel is best.

 

so 20w50 in FL is not a bad idea?

 

i used 5w20 for the first 40 000km that i owned my 8 and the engine went. probart mazda in london replaced the engine with out any issues even though i've been doing my own oil changes. they did ask to see the receipts for proof of proper maintenance which i never provide, they still went ahead and replaced then engine under warranty. on my new engine ive been using 5w30 and haven’t really noticed to much difference.

 

oil injections, MSP16 update just came out for the 8, after what 4 years of the car being out, ridiculous. If you ask me, everyone should use oil like the japs, and invest in a cobb from MM for updated OMP injections.

 

xxxrx8xxx you must be right. I have only been with Mazda for 20 years and raced rotaries for many of them so I am sure I have no basis or facts for my opinion. You do whatever makes you happy, I was only pointing out the reason why 5w20 is used in North America. This is again why I had previously stopped participating in these forums, and will cease again in the future. Btw, check the burn rate of 5W20 vs other viscosities and you will see the emission effect and why 5w20 is used in North America. Also I guess you never heard of using lighter weight fluids in your cars engine and driveline to increase rear wheels horsepower.......

 

hey #84 i was just trying to be helpful for all and get the best info for all so our cars run great. Hey if u raced cars for 20 years then that is great and you must have great experience ....All the stuff i have evidence on is from the net so some stuff is true and some might not be. But do you agree that there has been a law passed back in 2005 for the emissions for U.S. and Canada where all the new cars it use 5w20, hondas, ford mazda..When i was at the dealership Mazda one time, on my print out receipt for oil change it read 5w30 and i went to the manager and he said dont worry at mazda we only use 5w20 for all our cars its just a misprint on ur receipt........and as for wanting to use 5w30 and going to the dealer why not bring ur own oil for them to use and when u get castrol gtx oil just put the 5w20 sticker on it ......it actually removes itself from the box .....so they don't complain just in case...i just want all the 8's to run great


tis all

 

As a Mazda dealer, we have the responsibility to our customers to inform them to best of our knowledge and also what Mazda Canada finds acceptable etc. I have personally been at Quality Assurance at MCI when they have torn down a Renesis engine to inspect and that included sending the oil out for analysis. As for a law regarding the use of 5W20 that cant be as our Mazdaspeed engines use 5W30 as per Mazda Canada. Also our BSeries trucks use 5W30. I do know that engines that run 5W20 have different seals (rotaries) and rings (piston) to accomdate the lighter oil. You must realize that the manufacturors warranty these engines and are willing to accept all costs if they fail as long as the customer maintains the car to their specifications. That alone is pretty good reason to stay within specs. I know as dealers we are not perfect and make mistakes as our employees are all human. We try our best, and I realize that with enthusiasts the bar is much higher. Anyone is free to contact me and I will give what advise I can, but please don't slam dealerships on the internet if your not happy. It doesnt make me want to help some who has insulted another dealer as we are all part of the same family. I do realize some are better than others in dealing with rotaries, so try and find one that will work for you.