Oil viscosity 20w50 vs 50

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Sorry guys. I'm not trying to create controversy, and I definitely don't live for conflict. But most are missing the point.

The replies are informative, but they don't address the question: why does the article "Motor Oil 101" by AE Haas on http://www.bobistheoilguy.com say that virtually all motor oils don't provide adequate startup protection, and that 0W-XX would be a better choice? My point is, why the discrepancy? Is the evidence presented valid? If so, how can that be resolved with the Mfg's recommendation? If no one knows that's fine. But please, don't imply that asking a question to gain knowledge is akin to thinking I know better than the manufacturer.
 
I thrive on the excess of information, so questions others ask on my own as well as corrections are appriciated, but theres no need to lash out, pointing out the fool. Back on to what xRotXB brought up, seems it all comes down to an arguement of whats best for start up? My concern is more when its at normal operating temperature and being ran hard? Is there a brand or weight more suited for the style of riding vs a commute to work on a sunny day? Or am i just asking all the wrong questions, dont deserve a buell, possibly mentally incapable of simplifying my life choices?
 
I did absolutely no research, but I do know a few things (or at least that's what I tell myself)

Almost as soon as the first start of an engine with that oil is complete, the oil has been 'damaged'. The ability to lubricate at the cold viscosity is diminished the more you start up a cold engine. The viscosity index improvers only have a certain amount of 'life' in them and before long you no longer have a multi-grade oil, you've got a single grade. That being said you're 20w50 will eventually become straight 20. so 0w50 will eventually because straight 0.

Therefore, 20w50 is good and viscous for cold starts when it's clean fresh oil, then it warms up to a nice consistency for a hot engine. And, over time as the oil breaks down it provides protection that is at least as good as straight 20.

So really it's as simple as that, Buell says 20w50 so that you can count on having at least 20. go to 0w50 and yes your oil will be a little better for cold starts... but how long before you're oil reverts back to straight 0, I bet it happens before the next oil change.

It's kind of a catch 22. 20w50 isn't the best for cold starts but the trade off is longevity of the oil's lubricating properties. while anything higher (30w50) is too harsh at start up to pass as a good trade off to oil life.

Motor oil 101 says 90% of damage is done at start up... that's because we don't run straight 0. and if we did run straight 0 that 90% of damage would be while running, not while starting.

IMO, my start up lasts seconds where as my running lasts hours. I'd prefer a momentary lapse in protection during start up than a complete lack of protection while running.

If you want the best oil, use a fully synthetic 20w50, as synthetics have been created to make up from what non-synthetics lack (as far as oil aging goes)

I hope my scatter brained reply is a good answer for you.
 
I joking mentioned mixing multiple fluids and weights, what would be the result of combined weights, a 5w30 and straight 50, do the oil revert to individual viscosities or average out?
 
With all due respect to everyone, I personally think everyone (engineers) that is will have different views on the topic and will publish articles that we'll eventually find as we research such as here.

I'm not surprised at all that we have found conflicting information. I don't think any of us are fluid dynamicists and have the capability to run many of these tests.


As for Buell's recommended oil. These engines are air cooled and run real hot (no argument there) so the naturally gets much hotter than in other automotive environments. As such a hot rating of 50 is a mandatory.

As for the cold weight rating - I'd almost say pick your poison. There are not too many of us that ride in temperatures where even a 15W would be too thick for a cold start. Don't forget, the oil pump is a positive displacement pump and will push that oil whether it's a wee bit thicker or not. Let's also remember that too thin an oil is a bad thing.

Additionally, as you add more and more polymers (0w50 (if that even exists) vs. 20w50) the oil (As far as I can remember) breaks down much quicker and is less stable - I'll have to find the reference again.


Not that the above really answers anybody's question :p

Oh - what about Harley - do any of you think that Harley required Buell to run 20w50?


Just another thought - anybody ever seen someone take a high weight oil to improve their compression numbers? Just a bit of oil in the combustion chamber before the test can increase the numbers :D

Ben K.
 
0w50 does exist, I've seen it used in diesel engines and typically can only be found by the gallon.
 
do the oil revert to individual viscosities or average out?
Click to expand...

5w30 + 50?

fresh cold start = (5+50)/2 = 27.5
fresh operating temp = (30+50)/2 = 40
old worn out = (~5+50) = 27.5 (if the 5w30 completely reverted back to 5)

so half and half of 5w30 + 50 will always be between 27.5 and 40
 
I hope my scatter brained reply is a good answer for you.
Click to expand...
jaimz, I'll take a scatter-brained answer any day over an inflamatory misinterpreted one :) Yes it somewhat makes sense. I think I just need to do more reading.

Additionally, as you add more and more polymers (0w50 (if that even exists) vs. 20w50) the oil (As far as I can remember) breaks down much quicker and is less stable - I'll have to find the reference again.

Not that the above really answers anybody's question :p
Click to expand...
Ben, this makes the most sense to me of any answer. If you find the reference, please pass it along (maybe in a PM so the forum doesn't go all Lord of the Flies on each other).
 
Should I drain the brake fluid before or after I let the air out of the tire?
Click to expand...

No need to drain it, just cut the line so that it leaks directly onto the tire. That should take care of every worldly problem you have actually.
 
Sarcasm is my second favorite -asm! I find sarcastic ******** far more rewarding than actual information. Kudos to everyone involved!
Click to expand...

[up]

I dont know everything, but I do know that oil viscosity isnt a new break through.

:p
 
Hey Crash, what side of LV are you in. I'm on E. Sunset. Need to ride sometime. 08 White XB12R
 
Im actually from southern cali but i often shoot to vegas stay on my families house boat on mead. Im suppose to make a trip here soon so ill keep in mind your in the area Snaps
 

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