Just how badly do we need 0wXX and 5wXX?

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Originally Posted By: Saab9-3
If cold weather visc is such an issue with sae30 and a person wants to stick with an sae30. why not just plug the block heater in all the time so the Oil is a little warmer at start up? Is there a problem with using the block heater or an oil pan heater all the time when the weather gets colder


What happens when your someplace you can't plug it in?
 
From my crude calculations a while ago, SAE 30 is pretty similar to 15w-40 in most cool to warm temps. Nobody is crying about 15w-40 in moderate cold.
 
The Form still needs some good comaprative visc/temp charts of popular grades. Charts I've seen did not have good scale. I wish I had the skills to make them up. Anyone???
 
Originally Posted By: Auto-Union
From my crude calculations a while ago, SAE 30 is pretty similar to 15w-40 in most cool to warm temps. Nobody is crying about 15w-40 in moderate cold.


Exactly. Using the vis calculator I compared Valvoline SAE 30 and Rotella 15w40 all the way down to 0F. The SAE 30 was still THINNER than the 15w40 at 0F. (Rotella 15w40 @ 0F = 8160.9 cSt; Valvoline SAE 30 @ 0F = 7612.7 cSt.)

As I've said before, with a VI of 113-114, the Valvoline SAE 30 could no doubt meet the specs for a 15w30 or 20w30. Likewise, Valvoline SAE 20 with a VI of 126 could no doubt meet the specs for a 10w20. (The VI of Rotella 15w40 is 135.)
 
Originally Posted By: Towel_Rail
Is kinematic viscocity truly so linear that a calculator can be accurate so far away from the data points?


For a Newtonian oil, yes--down to the freeze point (obviously). For a non-Newtonian oil (i.e., multigrade), yes--absent shearing force.
 
Neat. Too bad they don't publish CCS and MRV data for the Valvoline 30. Pour/freeze point is one thing, but it doesn't tell the whole story.
wink.gif
 
Originally Posted By: G-MAN
For a non-Newtonian oil (i.e., multigrade), yes--absent shearing force.


Hey, that's not playing a straight bat !!

The shearing force defines what is going on in bearings and over the nose of the cam...thus your like of no VII.

Does describe low shear (like pumping) OK IMHO.

hmmmm....never argue with a bloke in an expensive suit :)
 
Originally Posted By: Shannow
Originally Posted By: G-MAN
For a non-Newtonian oil (i.e., multigrade), yes--absent shearing force.


Hey, that's not playing a straight bat !!

The shearing force defines what is going on in bearings and over the nose of the cam...thus your like of no VII.

Does describe low shear (like pumping) OK IMHO.


That's what I was talking about: the static vis at colder temps.
 
Any idea the HT/HS of 30 vs multi grades w/the same +100c?
My Delo 30 is an HDEO, I assume that means a HT/HS>3.5cP@+150c and HS, light operating temp visc. If I want a winter oil for the same application, I'll drop in 10w-40 Havoline DS.
 
Originally Posted By: Bluestream
Originally Posted By: [RT
ProjUltraZ]
Originally Posted By: Bluestream
I have seen -40F three times in my life. If you have never been in those type of temps; it's like going to another planet.


omg that's worse than stalingrad


Perhaps, but the women were better looking!


hey! are you saying russian women aren't good looking? i would have to greatly disagree there!
 
Quote:
P.S.: So far I see no data to backup you claim.


For criminy sakes! Why can't you just take the guy's word for it? I actually find scientific technical data to be boring as all [censored]; I'd much rather hear someone's personal experiences with an oil as opposed to some guy in a white lab coat holding a glass beaker.
 
Originally Posted By: Auto-Union
Any idea the HT/HS of 30 vs multi grades w/the same +100c?


Got the 2006 Caltex catalogue yesterday.

For 30 weights, HTHS is to be over 2.9

For 40 weights.
0W, 5W, 10W -40 ,ust be over 2.9
15W, 20W, 25W, and straight 40 must be over 3.7.
 
Here are some numbers from Penzoil Long Life HDEO PDS's...

10w-30
VI: 144
Visc.@100c, cSt: 11.7
HTHS, cP: 3.5

15w-40
VI: 136
Visc.@100c, cSt: 15.8
HTHS, cP: 4.3

10w
VI: 126
Visc.@100c, cSt: 6.5
HTHS, cP: 2.4

30w
VI: 107
Visc.@100c, cSt: 10.9
HTHS, cP: 3.8

40w
VI: 103
Visc.@100c, cSt: 14.4
HTHS, cP: 4.6

50w
VI: 102
Visc.@100c, cSt: 19.0
HTHS, cP: 5.7
 
Thanks for sharing the link.

A quick look brings an increased understanding for those that want a good sense of their oil in it's most basic form, a viscous fluid, from in the valve cover to eventually out of the pan. Yes there's the VI of the oil and the temp it sees in use. There's the vital wear control and anti-oxidant additives, etc. But it's nice to know, unless something such as fuel or coolant should contaminate the fill, the viscous fluid would not morf or act differently when times a test'n in a lubricant's first line of defense - viscous fluid film. I know however that some lubricant bases momentarily thicken under extreme stresses, almost counter to VII shearing...I wonder if there's some balanced thinking in formulations with this in mind ???

Not that the sky has/is falling with oils containing VII's mind you. It's just a BITOG thing I think. Something purest like...

More to mull over
wink.gif


Take care.
 
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