Quote:
Originally Posted by epinfren
I don't understand how there is still so much ignorance regarding oil in 2016, especially on a board devoted to an enthusiast model.
The number before the W in an oil is the cold weight of the oil. The second number is the weight at full temp. (Cold Weight)W(Hot Weight)
Both the 0W40 and 5W40 are 40 weight oils and will have the same thickness and film strength at full operating temp. Where the 0W is SUPERIOR to the 5W is at cold start up. The 0W is thinner only at start up so the motor turns over easier and the engine has proper lubrication the moment it cranks. It is not a thinner oil overall and/or at operating temp, only at start up where you want the oil to be thin.
Also, any 0W oil will always be a full synthetic. There is no such thing as a 0W conventional.
|
OK let me start with this my fellow car loving brother. As you can see by my length of time here, I have been on here a long time and I have never seen anyone change their opinions online. It is a useless endeavour but some of us are gluttons for punishment. I have two kids....despite being peed on, vomited at, sneezed at, being up all night for the 4 years straight I went ahead and had a second child. So those are my credentials to address your statement.
First let me start with this. You are 1,000,000% correct with with your "technical" review of the facts and 99% here know that the lower viscosity number is cold weight, etc. No one is disputing that or is ignorant unlike the Birthers that believe bashing a car with no miles is actually better for it.
So we have that out of the way. I am agreeing with you and the only reason I am putting such a long reply despite being in agreement with you on the technical accuracy you brought up is because I am the original poster.
So again, I do not disagree with you but I also understand why many are skeptical and nervous about 0W oils.
First Reason History.
Dr told women Thalidomide was good for pregnant women. Later it caused birth defects.
Dr.s said Eggs and Butter bad and margarine good. Peanut Butter and Avocados were high in fat and cholesterol. Now, natural peanut butter is good as are eggs and real butter.
Hang in there, I'll get to cars...
BMW recommended periodic transmission, diff and fluid changes in their cars. Then around 2003, the exact same car with no mechanical difference became lifetime fill fluids. As soon as BMW started to pay for service, the coolant flushes, brake fluid intervals doubled.
Those that are cynical believe it was because now that BMW was paying for the service, they simply decreed longer intervals. So you can begin to see a pattern here I hope. My 2011 BMW 1M motor is no different internally than most other N54 motors yet for my M version, they gave me a 1200 mile old school break-in that was not afforded to non M motors that were identical!
So manufacturers do things for THEIR interests not yours and many understand that which is why they are skeptical! I have never left oil in my car for two years and 15K miles nor have I left the same transmission oil and diff oil for the 15 years. Guess what, BMW has now backtracked from the lifetime fill because they experimented with a generation of cars and realized that transmissions were failing at 90K miles.
So why are manufacturers going with 0W oils. If you believe in the tooth fairy, you assume that it is because of less engine wear during cold starts. I'm sure that is part of it, the non tooth-fairy crowd believe it has to do with meeting tough fuel consumption standards. With a thin oil there is less parasitic drag especially when cold and you can start driving immediately. Also, you can designate one oil that will work worldwide! That is a very cool thing. In the past, you were given oil options based on average temperatures.
So the question then becomes, do you want to put the best possible oil for your temperature range or want a jack-of-all-trades oil designed to be OK in the Siberian winter? If there is in fact no trade-off with the zero weight, then that would be fine. But the non tooth-fairy believers think that there are always tradeoffs! It's too good to be true and we wonder if BMW is again experimenting on our dime with our cars.
There are engineers that believe that the thinner oil, even if it is only during the warm up stage is passing through valve guides, rings, etc causing consumption and worse yet blow-by that can create carbon build up on valves, especially in direct injected motors.
Now if you live in a part of the country where it gets really cold in the winter, then a little extra consumption would be worth it so you don't have congealed oil even though 5W is already pretty good at preventing that. But what about people like me that live in hot climates and get sunburned in the winter and store our cars in garages? The tradeoff benefit of a 0W vs a 5W might not be worth it if there is a chance of extra consumption and blow-by.
I have attached an image of a Consumer Reports article where they discuss this and I will include the link also.
So to summarize.
0W is being used to reduce fuel consumption and to have one oil that works worlwide.
Some believe that there are trade-offs. If you drive a lot and lived in cold climate then the benefits of 0W probably make sense. The oil flows quickly and I save on gas.
If you live in a hot climate and drive it very little then you might not want to make your dream car part of the 0W experiment because in a hot climate, there is less benefit to 0W.
http://www.consumerreports.org/cro/n...-oil/index.htm