Charles R. Hill

iTrader: (7)

bean, no disrespect but I was taught that the proper way to read viscosities was that the first number refers to the actual viscosity of the oil at room temp (more or less) and the second number refers to the weight the oil mimics (using your terms) as it gets hotter. Put another way, a 5W20 oil is a 5 weight oil that maintains its viscosity in the same manner and heat range as a straight 20 weight. This came from an API published textbook on the matter. You first sentence refers to the nature of a straight 20 weight oil.

Perhaps the confusion on which oil to use stems from the viscosities mentioned by racers who use 0 weight synthetics for efficiency purposes. Given that their oil gets changed after every run/race they have a little more lattitude in choosing oils/lubricants.

Charles

bean438

You are correct, but I screwed up the first sentence. I meant to say 0w20 starts of as a 0 weight. Lots of people confuse the w with winter.
the first number of the oil is the actual viscosity of the oil. 5w20 is a 5 weight.
The second number is the viscosity the oil mimicks when hot.
The oil itself doesnt really wear out. The additives that allow it to "change" to a heavier weight do.
The bottom line is to still go by what the owners manual says to use, and how often to change it, not what other people or oil companies say you can use.

Charles R. Hill

iTrader: (7)

Correctumundo, bean, and your further commentary on additives/detergents is also right on. Ditto on what the manual says but we need to keep in mind that the manual assumes certain parameters that may not apply, like specific use of the car and such. Good to have people like you around with solid info to share. Thanks.

Charles

Cam

iTrader: (1)

Per Mobil 1, they do not recommend it for Rotaries (per Mazda). I love Mobil 1, I used it on all my piston cars.

From Mobil1.com below

Using Mobil 1 will void my new-car warranty.
With the exception of the Mazda rotary engine (Mazda does not recommend any synthetic motor oils), Mobil 1 with SuperSyn™ will not void new-car warranties. Mobil 1 with SuperSyn™ exceeds the API and ILSAC motor oil service requirements of all new-car manufacturers, both import and domestic. If in doubt, always check your vehicle owner's manual or contact your vehicle's manufacturer.

http://www.mobil1.com/index.jsp


Dont shoot the messenger, Im just posting what is on Mobil 1's site. I am aware our owners manual does not specifically states synthetics cannot be used.

islandsoon

Cam I checked out your link above. The site isn't kept up to date. It doesn't even list the RX8 in the drop down menus when looking for what oil Mobil recommends. It only lists the RX7 in which Mazda was pretty specific about not wanting us to use a synthetic oil. I recall they changed their minds on the RX8.

Baller

They are talking about the RX-7 and prior.

Cam

iTrader: (1)

I noticed the same thing as well, but didnt know if the site was outdated or that the 8 wasnt listed due to syn not being offered for the 8.

bean438

If you read your warranty booklet it specifies to use required fluids as specified in your owners manual. Not Mobile 1's web site, Amsoils web site or even Mazda's website.
As good as the RX8 club is, it too is not to be followed for warranty issues.
As long as you use the fluids specified in the owners manual you will be fine.
API SL service rating, ILSAC GF 3, 5w20. That is all you need to know.
Charles I see what you are saying about certain parameters, but the bottom line is that this is not a race car (well it is kinda). It is a passenger car that will most likely be driven by average everyday people who happen to have impeccable taste in cars.
There are people that know way more about oil, and cars than I do. They may feel comfortable with deviating from Mazda's specs.
I am not one of these people. Part of the purchase price of my 8 includes millions of dollars of reasearch by people smarter than I am that have decided what is best for my car. They spell out the info quite nicely in my owners manual.
It is my bible and I shall heed it's word.

Charles R. Hill

iTrader: (7)

bean is correct in saying to stick with the owner's manual. I guess one way to view it is that if you need to ask about which oil to use, then stick to precisely what the manual says. If you are racing your 8, then the best place to get that info is from fellow racers who also have 8's.

Charles

bean438

Correct. However safe or not, using a straight oil/racing oil/whatever oil will certainly not work in your favor should you have to make a warranty claim.
That being said, using your car for anything other than regular driving will void your warranty anyway, so I guess it doesn't matter.

Gomez

In the interests of educating new members of the forum, I re-submit the following letter from Mazda Australia......make of it what you will. Do a search on my old posts if you wish to know more....

Happy Hunting,

Gomez.

bean438

Interesting pictures. Who actually has possesion of the letter? Who is MC?
If synthetic oil was an issue it would state not to use it or it is not recommended.
Mazda Canada web site (owners link) has an f a q that also does not recommend the use of synthetic oil.
If my warranty booklet said I must use fluids specified in the f a q section of the Mazda Canada web site then I would not use synthetic.
It says follow the manual.
Anyway I hate to beat a dead horse.

Gomez

I have it...., got it from my local dealer. MC is Mazda Corporation (Japan)...

bean438

Silly me! I should have known MC was Japan. I was thinking Mazda canada but then after I thought hmmm Mazda IS Japan. Thats where it all starts.
ANyway do as you may. The only information I have that is legally binding for warranty issues are my manual and warranty book. That is what I will follow.
Why would MC have sent you that letter? Why not Mazda Austrailia?

Gomez

MA generated the letter....they stated that they are getting their oil from MC. I received a copy of this letter from my dealer at my first service when I asked about the synthetic vs mineral oil debate....

Gomez.

Nubo

If you use Mobil 1 your car will develop pimples on the oil injector pump. You will get unexplained pig noises from behind the left rear passenger seat. And, buttermilk biscuits will begin to taste strange to you. It's not worth it, man!

bean438

Damn, so much for Mobile one!

bxb40

Mobil 1 Full Synthetic is great because of its low tendency to evaporate (in between other things). That is associated with poor burning characteristics - and, unfortunately, the rotory needs to burn it quickly.... Use any synthetic blend would be the safest to do - but not fully safe as Mazda did not test them in the RX-8. Unless the oil dealers use is actually a synthetic blend, as the service manager claims but was not sure As for what weight, it will depend on your location/weather/dealer recommendation. In US they like 5W20 for fuel efficiency reasons (imagine how worse it might look if using another grade )

fightersclubtv808

this may sound a little ignorant, but i just had my rx8 serviced at my local dealer, and put the synthetic question to them. the head mech specifically told me that because the rx8 rotary engine consumes a bit of oil (needs to burn it w/ the fuel) that synthetic oil is asking for problems because it will not burn. does this make any sense to anyone?

Gomez

Do a search using Gomez as the user name and Synthetic as the key-word. Welcome to the internet...

bigblockbeater

mazda specificely states they do not recomend synthetic. that's all i got to say about that

bean438

Where exactly do "they" or "them" or whoever state this?
I was given no document stating not to use synthetic oil.
The owners manual does not say synthetic is bad, and will eat seals/will not burn/has no ash/has too much ash/burns too clean/not compatible with rotaries/blah blah blah.
The manual also doesnt say to use conventional oil.
API SL service rating ILSAC GF 3 5 w20.
That is all my manual says to use.
As far as I know every other manual in the world also says the same thing.
Besides 5w20 oil for whatever reason (from bobtheoilguy forums) is a semisynthetic.

bean438

When my car went in for the 1st oil change I also asked the service manager about synthetic oil.
He said "they" dont recommend synthetic oil. I asked him who "they" was.
"Uhh Mazda Canada" said the service manager.
"Interesting, could you please provide me with something in writing from Mazda Canada that staes this"? asked the customer.
"I can do even better, you already have it in writing", proudly said the service manager.
"I do"? asked the customer.
"Yes it is in the owners manual that came with the car" said the service manager.
"Well I read the manual and no where does it state NOT to use synthetic oil" said the customer.
"You must be mistaken, I was just reading a manual the other day" said the service manager.
"Let's have another look then shall we"?
As the service manger flipped through the owners manual his facial expression changed from that of a I'll show you who is stupid damn customer know it all, to one of a very confused person. As he paged back and forth, making weird noises and muttering to himself.
"Thats funny" says the service manager, "I cant find anything about synthetic oil"
"Hang on I will get the mechanic who we sent to the RX8 seminar in here"
In walked a man in a mechanics uniform with his name embroidered on an oval shaped crest.
"Frank", asked the service manager, "Do you recall if Maz Can said anything on synthetic oil"?
"Ya", said Frank, "they didnt say one way or the other on synthetic oil, just 5w20 and make sure it is API cerified. The synthetic was an issues with the older rotaries, and it was actually more of a concern with the additives more so than the oil base itself. It was either a certain additive package, or 1 or 2 companies that had the seal issue. It was easier to just say no period."
"Uhhhhhhh yyyyyyya, ok well there you have it. There is the answer" said the service manager.
"Thats kinda what I remembered reading the other day".
"Where is that free coffee you guys have"? asked the customer.

Nubo

I don't buy the whole "needs to burn" argument. The oil isn't injected as a mist into the air/fuel charge for combustion. It's more like a very slow drip -- just enough to keep an oil film on the seals and housing. I'd think that the "burning" isn't taking place in the engine but rather as it is scraped away and "excreted" into the exhaust and catalytic converter.

fightersclubtv808

Thanks for the info on synthetics--the smug mechanic at my local dealer still stands by his "no synthetics" arguement though. So I head to my local auto store and find that they do not carry synthetic in that weight... could be because I'm here in Honolulu, HI--try and get coconut oil on the otherhand, and they have every type possible, too bad I don't drive Gilligan's bamboo car. So I buy Penzoil 5w20 instead... any bad experiences w/ this brand, or does the brand make a difference?