rotarygod

That's a fair question but we must also ask why are there different oil formulations for different parts of the world? That may shed some light on it. I don't think it's as simple as saying it's only because of emissions or mileage. It would be far easier to formulate 1 oil for all countries and just have the oil meet the spec of the most stringent of those countries. The question I have isn't why does the US get 5W20 and not 5W30. To me the real question is what is better about the US oil formulation that allows us to get away with 5W20 when others can't? I've always thought the European oil was the better one. I think think this should be looked into.

nycgps

iTrader: (1)

Thank you. I was about to say that.

Thanks.


The reason Im so against using 5w20 is -
- Its pathetic to begin with, damn I mean, they created that crap for better C.A.F.E. ratings, and we all know what that means. they're "willing" to give up engine life for that last drop of mpg they can get outa the car. so no.
- Heavier oil has better strength. period.
- Pictures of 5w20 engine 13B-MSP. and pictures of 13B-EGI 20w50 engine. I know its different in many ways, but certain stuff is the same.

IMO, I think Xw30 weight is bare bare bare minimum for this type of engine. 10w40 will work for most climates. but if you push your car a lot (like me, ahh I wanna go fast!), 20w50

rx 8speciale

iTrader: (3)

blabla all the threds i read saying that heavier oil was better for or engines and know everybody changing sides and weight , now lower s better ... ahahha i stay with 5w 30 since im in europe. good thread , again

nycgps

iTrader: (1)

I think its all the same oil. like Castrol Syntec 0w30 European formula is the same as the one they sell in Germany (thats where it comes from)

ITs just that we have something called "C.A.F.E." here. and we penalized the **** outa those auto companies if they dont follow it.

what should they do? just use whatever as long as it can get them the BEST mpg while making the car last thru-out the whole warranty period. After the warranty? hmm, good luck.

r0tor

iTrader: (1)

For more than 30 years, ExxonMobil has collaborated with some of the top motorsports teams in the world. This enables us to test our products in some of the harshest, most demanding environments and to use this experience to develop the next generation of high performance lubricants.

Mobil 1 Racing oil technology has been developed using our extensive experience in premier automotive racing series around the world, such as Formula 1, NASCAR, Le Mans, IRL, NHRA, Formula 3, SCCA GT, and ALMS. The variety of demands that each racing series requires of a lubricant helps us ensure that Mobil 1 Racing oils can meet the more extreme conditions encountered on the race track.

Available as:

Mobil 1 Racing 0W-20
Mobil 1 Racing 0W-30

yup, its clearly impposible for a lightweight oil to have any kind of protection and clearly a W20 oil is only good for CAFE. Truth is in racing they were using light oils before they were even available to the public. Of but thats right, racing oils are all think as sludge. Your knowledge of oils is poor. Your knowledge of how a babbit sleeve bearing works is poor. Your judgement of how most renesis engines are blowing is even more poor. I bow to you master

i'm completely out now

9krpmrx8

iTrader: (46)

You are right RG. This is a lot of info to absorb and apply.

nycgps

iTrader: (1)

Yep. you do know that these people rebuild their engines MORE often than you post in this thread, right ?

there are 10 weight oil, why dont you go ahead and use that ?

and u still trying to dodge the question of "why are we getting 5w20 and not rest of the world"

explain that please.

9krpmrx8

iTrader: (46)

But I'm still more on the side of protecting my engine at startup is key to longevity.

nycgps

iTrader: (1)

there are something called 0w50 or 5w50.

but I never trust oils with such super duper ultra wide viscosity range.

Mazmart

iTrader: (12)

I'm not sure which of my statements or comments offended you. I didn't start this thread although I quite enjoy the information that is put forward and the opportunity for learning in such threads.

Again if there's something that I've said that has you stirred up let me know. I'm not in the '**** them off' business.

Paul.

carbonRX8

iTrader: (1)

I am quite sure, Paul, that Team was suggesting that you post should have been the end of this thread as it is quite wise and informative.

I don't believe he meant it to be a slur on you, just towards teh uninformed blather that the thread was and continues to be.

That is not to say that there is not informative material here. But there are alot of assertions that MAY BE TRUE, but are as yet unsupported.

Why didn't you respond to my PM Paul?

rotarygod

I think this thread is different from past oil threads. This has some very different info to discuss and is far more than just the old synthetic vs conventional debate. This is getting into science.

carbonRX8

iTrader: (1)

Agreed, but it bothers me to no end when a poster uses post quantity over data quality to beat an issue into submission. Even when I agree that the assertion is likely true.

But yes. I am very pleased with this thread overall

nycgps

iTrader: (1)

I believe in science. (from Nacho Libre)

carbonRX8

iTrader: (1)

But alot of what you are posting is not. Again, I say this with respect and I am in agreement with alot of what you say.

nycgps

iTrader: (1)

Well, when I said "previous owners use 20w50 and they're ok" thats not science

but the reason why they use it? that's science

and more and more and more ...


ok. need to work on the FC again, grrrrrrrrr ....

LionZoo

Correct. One oil manufacturer's 5W40 might be closer to another's 5W30 than 5W40. I have noticed a thread toward formulating oils that are on the low side of the viscosity rating's range.

rotarygod

I need to go back and reread Dr. Haas' thread in more depth. What I can't figure out is where did he decide that a Viscosity index of 10 cSt was the goal? At first I thought he said that all oils regardless of weight have roughly that at 212*F (100*C) yet that isn't the case. All 30W oils, whether it's straight 30W, 0W30, 5W30, 10W30, etc fall somewhere between 10 cSt and about 11.5 cSt at that temp. Different weight oils have different ranges. A 20W oil will fall between about 8.25 - 9 cSt. A 40W oil will fall between 14 and 15.5 cSt. A 50W oil will fall between 17 and 19 cSt and a 60W oil will top 22 cSt at 100*C. I'm not sure why he is picking 10 cSt as the goal.

I think the point he might be making is that if your oil is thinnest at it's max rpm and load at max temperature, then having an oil that is thicker than this when cold at no loads isn't doing any additional good. There's alot to digest and I suspect some of what he's saying may seem a bit vague. One thing I've found when writing long tech related topics is that you may know something very well but when writing it may not explain it all that clearly despite your best attempts.

The one thing I am getting out of what he writes is that he seems to believe that you should be running an oil that is thin enough that you don't hit your oil pressure bypass until max rpm provided you can still maintain at least 10 psi per 1000 rpm as your flow is down. This of course will be dependent on oil temperature which is something else I got from it. If all you do is cruise down the highway all day, your engine isn't really working and the max oil temps inside the engine will not be all that high (relatively speaking of course). This engine may benefit from a lighter oil as it never heats it up enough to make it too thin to hit oil bypass. However the same engine on a track that is constantly off and on the throttle hard and high rpms, putting out extreme heat, will get the oil much hotter internally, This means thinner oil (or less thick oil). Now you could hit the same issue. Your hotter thinner oil doesn't hit bypass. The solution? Thicker oil. This all makes sense.

What is vague is how do we determine what max oil pressure we should run? Different rotaries of different years had different oil pressures. Which is optimum and how do we figure this out? If we have enlarged oil passages that have been cleaned up and flow better, we also have more flow but less system pressure. How do we know that we need to add more pressure from the pump as opposed to running a thicker oil? How do we know that any 1 target cSt is the optimum number to shoot for? Why is 10 cSt better than 8 cSt or 15 cSt, or vice versa.

Dr. Haas has given lots of good info but in the end it's only creating more questions. I do think it is leading us down the path of truly beginning to understand oils though so there is a benefit. For once we can focus on what makes an oil better rather than arbitrarily saying one is. There's alot to it and it's going to take a while to sort out.

9krpmrx8

iTrader: (46)

Amen. I am trying to take a more positive approach to life lately so personally if I don't like a thread I try (I still cannot resist sometimes) to just not post rather than post something negative. I have been a part of many of the past threads and this is one of the first where there is an explanation to the data rather than random 'experts' posting useless info.

I just think a lot of people want there to be a definitive answer to the question of what oil to use and really there is no one answer fits all. I think RG is on to something with regard to people just sticking to old habits and traditions.

PhillipM

Perhaps you missed this bit in there:

Now, last time I checked, rotaries don't use huge bearing clearances, unless you've replaced them with deep groove race-bearings to reduce friction at the expense of bearing life?

LionZoo

I took his 10cSt number as simply a comparison baseline. He certainly didn't explain the logic behind the number, so I don't see the need to follow that as the bible.

What is also a good point is that while start up wear is a huge percentage of wear in the life of a normal car, it once again comes down to how you drive it. If you drive your car hard for a long time, it might be that hitting optimal viscosity at operating temperatures while being 80% off at cold start up is worth more than being optimal at cold startup, but 20% off at operating temperatures since your engine spends a physically longer time driving hard. Once again we have to be honest to ourselves.

Besides the RX-8, all the rest of my family's cars get the same brand and weight oil even though the different engines have different recommendations. Is it because the oil X that I use is what I believe is optimal for all cars? Actually not; it simply makes my life easier to buy the same oil for all the cars and I feel that it certainly gives more than enough protection for the life of the car that we're planning to keep them for. There's certainly other factors involved (I DO believe that oil X is very high quality oil), but the driving motivation behind getting the same oil and same weight has to do with simplifying my life. And sometimes I'm sure the same logic is used for oil recommendations for a line of cars. Manufacturers want to standardize the oil weights so that they don't have to stock a five weights for five cars they're manufacturing; that's hell on inventory. If you use one weight for all the cars you eliminate four part numbers and in manufacturing that's a huge gain. Coincidentally or not, I think pretty much all the Mazdas now recommend 5W20.

PhillipM

They're fine if they're a proper ester synthetic, it's when they starting adding huge amounts of polymer additives to a thin base oil and it breaks down as the milage piles on...

nycgps

iTrader: (1)

as for the "deep" groove race-bearings, wow, I mean its just another what, 0.0005 inches of clearance ?

if it works for "that"(the race-bearings with extra clearance), I dont see a problem using 50w oil for stock bearings.


For those who dunno, 12A and all 13Bs sharing the same Rotor bearings.

rotarygod

I know the case for thin oils is startup wear. It's that a thinner oil will be easier to flow when cold so it therefore gets to the bearings faster. However lets say we have an ambient outside temperature of 75*F. We can easily see that 5W20 and 20W50 both pour pretty easily. While the cSt numbers may appear very different on paper, from a functionality standpoint is there really going to be a problem? If the oils are both thin enough that the pump has no problem moving them then I don't see the issue. Keep in mind that a thinner oil that flows better also drains better which means a thinner oil will drain off of your bearings when not moving to a greater extent than a thicker oil will. That leaves less oil left for the next time the engine turns over.

As with everything there is a balancing act. I think looking at the centistoke numbers for viscosity is a good thing but I don't think it's telling us the whole story in the real world. It would really only seem to be a large concern during temperature extremes such as starting a cold engine in North Dakota in January or running wide open for 12 hours at Sebring. However with less extreme temperature environments, both inside and outside of the engine, the actual weight doesn't seem to be as critical. We know engines can run fine on both 5W20 and 20W50. At least they can in warm climates. There is a point where damn near anything will work decently. However I wouldn't want to run 20W50 in North Dakota in the winter and I wouldn't want to run 5W20 in Phoenix in the summer.

While something may work great on paper, we really need to ask ourselves, is it going to give any functional benefit in the real world?

nycgps

iTrader: (1)

the "Ester" is the problem, not much ester synthetic out there. Redline is one, Eneos is another. a few more.