proof of 0w oil being better than 5w?

fouillard13

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Hey guys, I remember seeing an awesome post here regarding 0W oil being WAAYY better for our camshafts than 5w oil... where is it? ive tried googling everything and cant find it.

thanks
 

Drivbiwire

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Faster startup lubrication, yes 0W is superior.

Don't confuse and do not make the mistake of focusing on the 0W when its the last number that ultimately protects your engine!

For Flat Tappet engines (VE/PD) a 0w40 is the ideal oil viscosity in temperature ranges of -54C to 60C+ ambient. A 5w40 just sacrifices that extreme low temperature range increasing that to around -32C up to the same 60C+ ambient.

That second number when accompanied by a HTHS rating of 3.6 or higher takes the oils ability to protect further to 150C not just 100C and how it can protect critical regions of the motor that operate at those temperature ranges.

Wrist Pins, Skirts, Upper Compression ring, Valve guides, Turbo (Turbine Seals).
 

fouillard13

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so im talking rotella t6 0w40 vs t6 5w40.

the 0w is supreior in every way, even in the summer its preferred to run?

I swear I seen a post here where they explained how the engine runs "dry" with no oil until its pumped to the top on initial startups. with 0w oil it was like 1 full second, with 5w oil it was double that.
 

turbobrick240

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I would think the Rotella 0w40 is equal to or superior than the 5w40 in every way. Probably has higher quality basestock. Oddly, I can't find the RT6 0w40 in Maine, but I found it at the first auto parts store I walked into in Austin this winter.
 

turbobrick240

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My guess is that Austin's proximity to Houston plays a part in the 0w40 being available there. Seems odd since a 0w40 really isn't going to be advantageous in Tx.
 

UhOh

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Viscosity is one thing, additive package is another. In the case of the PDs the additive package is as important as viscosity (keeping in mind that most all available viscosities for oils recommended for these engines are in a fairly confined range).

0w-40 IS available here in the US (just a quick grab/search):

http://www.oreillyauto.com/site/c/d..._MOB_-1_-1&mn=Mobil&mc=MOB&pt=N1186&ppt=C0252

Note, however, that this is not appropriate for DPF equipped engines.
 

turbobrick240

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The 0w40 In the link is Mobil1, which has been widely available for many years. A good oil. But the Rotella T6 0w40 has a CJ4 rating and .is more tailored to diesel engines.
 

UhOh

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The 0w40 In the link is Mobil1, which has been widely available for many years. A good oil. But the Rotella T6 0w40 has a CJ4 rating and .is more tailored to diesel engines.
Yeah, I just grabbed the first thing I could find. I've run 5w-40 T6: currently running Delo 400 LE. CJ-4 IS the ticket for the VE engines! (PDs need additional additives- cam).
 

BobnOH

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Hey guys, I remember seeing an awesome post here regarding 0W oil being WAAYY better for our camshafts than 5w oil... where is it? ive tried googling everything and cant find it.
thanks
You're kidding right?
There are hundreds if not thousands of posts about oil.
Then there is Bob the oil guy.
Maybe this user contributed search engine will help.
(use the search dialog near the center of the page)
 

fouillard13

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Viscosity is one thing, additive package is another. In the case of the PDs the additive package is as important as viscosity (keeping in mind that most all available viscosities for oils recommended for these engines are in a fairly confined range).

0w-40 IS available here in the US (just a quick grab/search):

http://www.oreillyauto.com/site/c/d..._MOB_-1_-1&mn=Mobil&mc=MOB&pt=N1186&ppt=C0252

Note, however, that this is not appropriate for DPF equipped engines.

I know theres 0w-40 in the USA via any brand... its the 0w rotella t6 that youll have a tough time finding... or so I was told.

regarding the post im talking about, im surprised no one here knows what one. it had pics of the cam at a microscopic level and everything. it was posted more than once.. its like a semi famous post.
 

Rembrant

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regarding the post im talking about, im surprised no one here knows what one. it had pics of the cam at a microscopic level and everything. it was posted more than once.. its like a semi famous post.
I'm guessing that it probably wasn't a "semi-famous" thread about oil that you're thinking of, but a semi-famous thread on PD camshafts...and even more specifically, the BRM camshafts. There are several members on here that were posting pages of their thoughts on oils along with magnifying glass images of their camshafts, etc. There are a couple huge threads on that stuff.
 

fouillard13

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it was a post by one ot the top dogs here, DBW or frank06 or something.... it was filled with nothing but info and facts!!

can you link me to that threads on pd cams?? maybe thats the one.

thanks
 

Ol'Rattler

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Ah no proof. For the BRM the call out is 5W40 speced to 505.01.

What really sucks is that the dealers dont even stock it. Their version of 505.01 is 5W30 that does not meet the called out spec for weight. So i quess if they can get you past the waranty, then anything they put in your engine is fine.
 

tikal

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The 0w40 In the link is Mobil1, which has been widely available for many years. A good oil. But the Rotella T6 0w40 has a CJ4 rating and .is more tailored to diesel engines.
Here is a version of a 0W-40 with the newest API CK-4 diesel rating:

http://www.amsoil.com/lit/databulletins/g3467.pdf

There is a little bit of trade-off between Pour Point and NOACK Volatility when comparing the 0W-40 and 5W-40 in this brand.
 

turbobrick240

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Here is a version of a 0W-40 with the newest API CK-4 diesel rating:
http://www.amsoil.com/lit/databulletins/g3467.pdf
There is a little bit of trade-off between Pour Point and NOACK Volatility when comparing the 0W-40 and 5W-40 in this brand.
Nice. I actually bought my first quart of amsoil 5w40 in Austin last winter. I keep it in the car for an emergency. Honestly, I was much more excited to find the Rotella 0w40. Probably because I can get the amsoil up here.
 

Geordi

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The way the engines are built, you could probably almost run them on fruit juice or just the original oil fill, and they would still pass the initial warranty period. It is that NEXT 100k miles and beyond, that they neither care about nor want YOU to care about - they want you buying a new car!
 

James & Son

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so im talking rotella t6 0w40 vs t6 5w40.

the 0w is supreior in every way, even in the summer its preferred to run?

I swear I seen a post here where they explained how the engine runs "dry" with no oil until its pumped to the top on initial startups. with 0w oil it was like 1 full second, with 5w oil it was double that.
Doesn,t matter how much lubricity an oil has If the cam stops for 10 seconds or more you will have metal to metal contact because the oil is absolutely squeezed out between the contacts.

It is impossible for oil to flow from the crankcase to the cam bearings and then flow by gravity to the cam followers in 1 second after sitting overnight. It takes about 4 seconds at room temperature for the followers to be immersed in oil.

When an engine stops and sits overnight the followers retain oil on their top surface. As soon as the cam begins to rotate this residual oil provides mixed boundary lubrication for the first 4 seconds. I believe the 5w-40 is the best compromise in lubricity at start up.

I have used a torque wrench to check the rotational torque of a BRM cam using different oils and cam springs. When I was using a 0W-40 Petro Canada oil it took about 30 or 35 foot pounds to initially move the cam due to metal to metal contact. By ratcheting as quickly as I could (about 8 rpm) I recorded 15 ft lbs.

Because I was playing with cam bearings and followers I had lots of opportunity to check this. It happened the next time I checked the torque at reassembly I was using a HD 15w-40 and had lub the followers with the same. Again it took 30-35 lbs to break loose but only needed 13 ft lbs of torque. When I tested a 15% reduction in cam spring force the torque requirement was 11 foot lbs and I am not curtain what oil I lubed the followers with.

The point is I don't believe you should use a 0w-40 unless their is a need for it such as Alberta in the winter averaging below -15 C. In general I believe i am better off with a 5w-40 and a coolant heater for winter morning starts. Usually the daytime temperture/starts are warmer and I live with that.

I would much perfer a high VI index oil in a 5W-40 oil than the same high velocity index oil in a 0w-40 as I live in Southern Ontario and I am not below -25C and average above -15C.
 

Windex

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5w vs 0w 40 weight Rotella is an insteresting choice.

I have found conflicting information on viscosities at 100degC,

In my experience, a 5w40 will always have a higher 100degC CsT than a 0w40.

From Shell's literature, T6 0w40 has a 100 degC Cst of 13.2, and 5w40 @ 14.09, but I have seen some higher values from folks who have done their own analysis.

Minor difference, but I'l take all the hot viscosity I can get with the PDs habit of eating cams. Mine's at 470k km and still original - has been on 10k intervals of Rotella T6 for the last 230k. I have no plans to switch.
 

TDIMeister

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The SAE designations for oils should be taken with large measures of salt. It does not correspond to an exact viscosity in cSt, but rather is on a considerable range and there can be overlap, say between 0W and 5W.

That said, the intrinsic parameter that determines viscosity is measured in cSt.

The hot (or cold) viscosity can be determined by having the other viscosity and the VI in much the same way you can determine the cartesian coordinates on a different point on a straight line using
y = mx + b.

The analog is that m is the VI and b is either the 40C or 100C viscosity; then you can calculate the viscosity at any temperature along the VI curve. Note that all this is done on log scale instead of linear. This means that the highest possible VI is always - almost without exception - better, since this means that it will be relatively thinnest at temps way below 40C and thickest way above 100C.



To answer the question about the suitability of any oil - 0W, 5W or otherwise - I would argue that the most important parameter is neither the SAE weight or cSt @100C, but rather the HTHS. If it meets ACEA A3/B4 and VW 505.00 (VE) or 505.01 (PD), you're good to go with any weight that's labeled on the bottle. Been using 0W-30 or 0W-40 Castrol Edge (both meet ACEA A3/B4 and VW 505.00) for years in my VE.
 
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Matt-98AHU

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This subject is far more complex than simple viscosity. There is a lot that goes into oil chemistry, anti-wear additives (or lack thereof for emissions reasons), detergents as well as what the oil base-stock is made of and how they all interact with eachother and your engine.

There are bound to be some 0w20s that protect better at high temperatures than a 5w40 just due to such differences in chemistry. How are you to know unless you start getting some real data with some used oil analyses on your own engine with various oils?

The one little thing that's got my attention lately are polar-ester basestock oils. They are magnetically attracted to oils and can provide an exceptionally durable film that protects well even during start up before oil pressure builds, they also seem to do exceptionally well at cleaning varnish/sludge from previous poorer quality oils that were used in the engine previously. But esters don't always go for as long of an oil change interval as something heavier with a Group IV PAO basestock, which itself has some excellent anti-wear properties, but may not stick quite like a polar ester and may also harden seals if it's a 100% PAO basestock. A good combination may be an oil with a balance of both.

It's a complex subject that's better left for hours of reading over on Bobistheoilguy.com as well as doing your own used oil analyses and tracking of wear metals over the oils you decide to try. May also be a good idea to look at virgin oil analyses of whatever oil you're using as well so you know how much of each additive and metals you're starting with before putting it into your engine.
 
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