See, here's the problem...

Your ambient temperature has almost nothing to do with the conditions oil will encounter while in your motor. If you simply stick to using a 5w or 0w oil then starting temperature will not make any difference.

Whether people think the chart is supposed to help you choose your oil or not, oil temperature is regulated via thermostat. It's like choosing your coolant based on your ambient temperature. It doesn't matter cause your operating temperature inside the motor is always the same!

So, choosing your oil based on how hot or cold it is outside is totally useless.

It has to be about 110 degrees outside before I start to see oil temperatures get above 210 degrees during normal street driving. Even still temperatures are easily controlled during normal highway driving.

Choose your oil based on how you use your car and not your environmental conditions.

 

I beg to disagree. Oil weight may not matter in Phoenix, but it does elsewhere. It gets cold here and if you try using a 50 weight oil here, your car won't turn over in the winter. If you do eventually get it started, the oil will be so thick that it won't circulate and you will damage the surfaces that require lubrication.

 

Mazda Australia recommend 'their' Mazda Rotary Oil" MRO made by Castrol 5W30.

I have scanned and posted before...you will have to find it...GRRR..

Stay Tuned..

here you go..

https://www.rx8club.com/australia-new-zealand-forum-37/rx-8-series-ii-owners-manual-engine-oil-161616/

 

I guess Oil Companies, car manufacturers have had it all wrong up until 2004.
So the "new" oil is 5W20.

Well in 2010 Mazda are still showing a temp graph here and many other countries except the US.

This is a fecking boring discussion..

 

Yikes, yet another oil thread.

Which reminds me.........who's running the "milky substance on my dipstick" pool this year? It's about that time!

 

Thanks for that, Ash.

I'm sure it's boring to the guys who've been discussing it forever, but for the new owners, we're just trying to get educated enough to make a good choice. It's pretty clear from the amount and heat of the comments that it remains, after 5 or 6 years of vehement debate, unresolved.

 

That's OK mate ...you look like a good young lad... with a sexy looking Blue R3...

FIRE Away at the questions...this old bastard really does not mind...GRUMP...

This is a recording...

 

Ash, honestly man you are killing me.

I'm a broken record repeating that 5w-20 or 0w-20 may not honestly be the best choice for the rotary. The point, yet again, is that Mazda probably got their viscosity choice more right than they did wrong.

Everyone makes comparisons to the RX7 but doesn't take into consideration how many oil standards we've had since then.

Counting the 1971 and older standard, there have been eight...yes eight oil standards that have been put into place since then. Counting the 1988 and older standards, we have had six oil standards that have been put into place.

For all I know, 5w-30 could be the optimal choice for daily street driven vehicles. Depending on the oil type a 5w-40 could be the best choice for race track applications.

The problem is many people who have argued this position keep pointing to the viscosity as the deciding factor for oil. As I've stated before it's like using horsepower as the deciding factor for your car choice. It's a narrow minded way to shop for cars AND oil.

Running 20w-50 or 0w-50 on a street driven vehicle, based on the information I've come across, is the complete wrong choice. Period. It's too thick at startup, it's still to thick at operating temperature. No one on this board is running 240 degree or above oil temperatures and probably 1% of people reading this post even know what their oil temps actually are.

High viscosity oils for "traffic" problems has been the only argument I've seen. The counter to this argument is the fact that you're running low engine loads and low speeds which means your lubrication needs are very minimal in this situation. Once up to highway speeds temperatures drop within acceptable limits. You're going to base your entire oil choice on less than 10% of your total driving?

I see complaints about bearing replacements yet no one can speak to whether or not these bearings were replaced because they were out of tolerance specifications or simply because they might show some wear. I happen to know for a fact that BHR has encountered bearings which have shown wear to the copper but are still well within tolerance.

You shop for oil based on three factors:
Viscosity, base stock and change interval.

Your viscosity should be based on the kinds of pressures you are seeing during your normal operating temperature. Street driven vehicles will see between 180 degrees and 210 degrees of normal operating temperatures. This means (in theory) that a 5w-30 would keep between a 10 to 12 CsT of viscosity within in this range. This would keep your pressures within tolerance and give you the most amount of flow for maximum lubrication.

For racing applications where 220 degrees or higher would be expected, a 5w-40 (or perhaps a 0w-50) would be ideal depending on where in the viscosity range it falls into.

Stick to a high quality synthetic with change intervals of 3,500 to 4,500 miles. Oil testing would be best to determine how long you can run a particular oil.

Six oil standards later I think it's safe to say that oil is totally different than it was when Mazda wrote the RX7 manual.

 

this site is loaded with threads chock full of information for n00bs to learn from, unfortunately information that in time has been proven to be badly wrong ...

 

Listen up noobs me included 5w-30 RP for tmfw how did I get so smart? rg, ash, fw, od, the bhr boys

 

Dang it i just put 20w-50 in my car T_T

 

Yeah you definitely have to take a lot with a grain of salt. Most people will swear by things with no hard data to back it up. I will sample, sample, sample and keep tracking my pressures, etc. My thinking has changed a few times regarding the whole lubrication issue.

 

so if its not 5w-20 or 20w50 then what is acceptable but then again it always comes down to peoples opinions.

 

Really man there is no answer for that without knowing your driving habits, maintenance habits, etc.

 

Drive the 8 on the weekends, redline a day, do some spirited driving on the side, check my oil level once or twice a week, change the oil every 3k miles.

 

Mileage? Original owner? I would say a 5W-30 or 0W-30 would do you fine but a used oil analysis could'nt hurt.

 

80k miles i just bought the car about 8 months ago but i think there were 4 prior owners. I dont know how to analyze oil. Would it hurt to run 20w-50 for 3k miles since i just changed it?

 

Wow, any engine replacements? if its 80k on the original motor without knowing the maintenance schedule then just put on 5W-30, the damage is probably already done but maybe all four owners maintained it, who knows.

 

Not that im aware of, would it hurt to run the engine on 20w50 untile my next oil change?

 

No, a lot of these talks of bearing damage or related parts would take ten's of thousands of miles before you're going to see serious problems.

I'm talking about oil choices that would mean the difference between 100,000 and 200,000 miles.

"Testing" oil isn't something people do themselves. It just involved shipping a sample to a testing lab that provide results based on the sample data.

For the sake of everyone's sanity, I would look at a 5w-30 or 5w-40 or variations of any 0w oils. There are going to be enough variations between types and brands that a 30w might be good enough or you might need a 40w to ensure the viscosity stays within safe ranges.

The point of getting oil tested would be two things. First, you get a snapshot of what is going on inside your motor. It helps show signs of wear, whether or not you might have a coolant leak or excessive fuel inside your oil. Second, it helps you determine if you're using a good quality oil with proper thickness. This plays into how long you can run the oil in your RX8.

Without hard data this is all speculation. No one is going to wait until they have their motor rebuilt to decide of they made good oil choices.

 

Nah, won't hurt anything. And you can check out www.blackstone-labs.com if you wanna send a sample of your oil in for an analysis. I have a thread started to post these reports.

 

I encourage people to participate in this thread as you'll be able to see real testing data for various oil brands and viscosities. It will save you from having to test 5 or 10 different oil types on your own.

 

ok ill keep the oil in there then for my next oil change i switch to 5w-30

 

Like I said, just looking for good info, Ash, and the help is appreciated. And that's one of my kids by the way, not me. And a younger one at that. My oldest is 37.

I've been doing a little off forum homework myself, asking BHR, RP, and RB for their opinions. It's not remarkable, I suppose, that they ALL recommended 0 or 5W-20 or 30. Coincidence? I don't think so. But please don't misunderstand. I am in full support of everbody doing their homework, drawing their own conclusions, and running whatever they think works best for them, 0w-0 or straight 50, it's all the same to me.

 

Flashwing that makes total sense to me. The average Rx8 driver what is that 99% of us red line it a day, drive average will push it now and then, don't live in 100+ heat everyday no tracking or autocross and we don't know our oil temps. Then 5w-30 good synthetic or if you're not synthetic fan then double flush like Ash recommends with a dino every 3,000 miles keep your premix a little and hope for 200,000.