So if the thicker oil does not absorb heat as quickly, then that means the heat is retained in the engine parts and therefore the engine will warm up faster, which is good is some respects.
Why use anything other than a 0wXX oil?
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Maybe...some of the great UOAs on GC are more from good start-up/warm-up visc than from HT/HS or +100c visc.
If the wear metals in a UOA reflect actual wear in the engine your statement above almost has to be correct. If 75+% of wear is at cold startup and GC demonstrates low wear - duh!quote:
Originally posted by Audi Junkie:
Maybe...some of the great UOAs on GC are more from good start-up/warm-up visc than from HT/HS or +100c visc.
Look at the Consumer Reports Taxi report. No difference in measured wear between any of the oils after 60,000 miles, however, cold starts were not a major factor in these tests.
Patman
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I honestly don't think so, since a lot of the really good UOAs posted by GC users are from the summer, where it's actually thicker than a lot of oils on startup (it's 40C viscosity is thicker than most 5w30s and some 10w30s)quote:
Originally posted by Audi Junkie:
Maybe...some of the great UOAs on GC are more from good start-up/warm-up visc than from HT/HS or +100c visc.
I think GC's good showing is simply from it's good base oil/additive combo. It's simply a well put together oil. Being a 0w oil doesn't really have much to do with it in a lot of the reports we see on here, since the people didn't drive in extreme cold during those runs.
with either 5w-40 or 0w-40 mobil 1 I see no difference in my Saab in the winter. I use M1 15w-50 in the summer. I still run 7000mi in a turbo car with 137000mi and absolutely no oil consumption. I thought that I would get some when I changed to syn, but I have had none to speak of. I am definitely a believer in the wide spread syns.
Another chart for your perusal.
Enjoy!
Hope this is what your after. You owe me a beer for all the reformatting.
You know I love you for it, and it really is interesting for comparitive purposes.
For example, I run Esso XD-3 Synthetic and I can see that it is quite thicker than Mobil 1 0w30 at the same temperature range.
Wonder if I did the wrong thing by using this oil?
Do you have any readings for Castrol Syntec 5w30?
For example, I run Esso XD-3 Synthetic and I can see that it is quite thicker than Mobil 1 0w30 at the same temperature range.
Wonder if I did the wrong thing by using this oil?
Do you have any readings for Castrol Syntec 5w30?
Google the oil specs, then go here:
http://www.geocities.com/CapeCanaveral/3655/VI.html
...and create the tables you want. Remember the previous caveats.
As fas as the XD3 values, I'm of the opinion that anything under 3500 cSt isn't a concern. Also remember the CCS, MRV specs are more applicable at the very extremes of coldness.
http://www.geocities.com/CapeCanaveral/3655/VI.html
...and create the tables you want. Remember the previous caveats.
As fas as the XD3 values, I'm of the opinion that anything under 3500 cSt isn't a concern. Also remember the CCS, MRV specs are more applicable at the very extremes of coldness.
For Castrol Syntec 5w30 I was using before:quote:
Originally posted by 427Z06:
Hope this is what your after. You owe me a beer for all the reformatting.
-20 2398
-10 1011
0 482
10 254
20 146
30 90
40 58.5
50 40.2
60 28.7
70 21.3
80 16.3
90 12.8
100 10.3
110 8.44
120 7.04
130 5.96
140 5.11
150 4.44
This is very interesting. Using the vis calculator (Module 3) and the figures in 427Z's chart, M1 5w30 is "thinner" than GC 0w30 until between -50C and -60C. I wonder if M1 5w30 is really a 0w30 in disguise, and who knows what their 0w30 is?
M1 shear down? I guess I've never experienced that, and haven't heard of too many people with sound mechanicals where that has happened either. And 0W too thin? Thin is "in", especially at cold start winter temps. I wouldn't use anything else.
Actually, the owner's manual on a 2004 Chevy Impala I skimmed last fall says you are reccomended to use 5W30 convetional oil, but you may use 0W30 synthetic if you'll be operating the vehicle in extreme cold.
Motor Oils - Fuel Economy vs. Wear By Blaine Ballentine, Central Petroleum Company:
Viscosity and Wear
Thinner oils have less drag, and therefore less friction and wear...
Any abrasive particles equal to or larger than the oil film thickness will cause wear. Filters are necessary to keep contaminants small. The other side of the equation is oil film thickness. Thicker oil films can accommodate larger contaminants.
Temperature has a big effect on viscosity and film thickness. As a point of reference, one SAE grade increase in viscosity is necessary to overcome the influence of a 20°F increase in engine temperature. At a given reference point, there is approximately a 20°F. difference between viscosity grades SAE 30, 40 and 50. SAE 20 is somewhat closer to 30 than the other jumps, because SAE 30 must be 30°F higher than SAE 20 to be roughly the equivalent viscosity.
In other words, an SAE 20 at 190°F is about the same kinematic viscosity as an SAE 30 at 220°F, which is about the same viscosity as an SAE 40 at 240°F. This approximation works well in the 190°F to 260°F temperature range. One might be surprised at the slight amount of difference between straight viscosity vs. multi-viscosity oils with the same back number (for example, SAE 30, SAE 5w30, and SAE 10w30).
If an SAE 50 oil at 260°F is as thin as an SAE 20 oil at 190°F, imagine how thin the oil film becomes when you are using an SAE 5W-20 and your engine overheats. When an engine overheats, the oil film becomes dangerously thin and can rupture.
Ford is bumping up against its CAFE requirements and recommends SAE 5W-20 oil for most of its engines in the United States. It claims SAE 5W-20 is optimal for fuel efficiency AND wear.
(If your engine is 20 F cooler running a thinner oil then the viscosity is the same as the next higher weight grade. Also, as wear diminishes with temperature then we have a benefit. Another benefit is that the thinner oil is better at startup where the majority of wear occurs. Looking at the above data 10 C cooler (140 C) is much thicker HTHS and therefore no penalty.)
aehaas
Viscosity and Wear
Thinner oils have less drag, and therefore less friction and wear...
Any abrasive particles equal to or larger than the oil film thickness will cause wear. Filters are necessary to keep contaminants small. The other side of the equation is oil film thickness. Thicker oil films can accommodate larger contaminants.
Temperature has a big effect on viscosity and film thickness. As a point of reference, one SAE grade increase in viscosity is necessary to overcome the influence of a 20°F increase in engine temperature. At a given reference point, there is approximately a 20°F. difference between viscosity grades SAE 30, 40 and 50. SAE 20 is somewhat closer to 30 than the other jumps, because SAE 30 must be 30°F higher than SAE 20 to be roughly the equivalent viscosity.
In other words, an SAE 20 at 190°F is about the same kinematic viscosity as an SAE 30 at 220°F, which is about the same viscosity as an SAE 40 at 240°F. This approximation works well in the 190°F to 260°F temperature range. One might be surprised at the slight amount of difference between straight viscosity vs. multi-viscosity oils with the same back number (for example, SAE 30, SAE 5w30, and SAE 10w30).
If an SAE 50 oil at 260°F is as thin as an SAE 20 oil at 190°F, imagine how thin the oil film becomes when you are using an SAE 5W-20 and your engine overheats. When an engine overheats, the oil film becomes dangerously thin and can rupture.
Ford is bumping up against its CAFE requirements and recommends SAE 5W-20 oil for most of its engines in the United States. It claims SAE 5W-20 is optimal for fuel efficiency AND wear.
(If your engine is 20 F cooler running a thinner oil then the viscosity is the same as the next higher weight grade. Also, as wear diminishes with temperature then we have a benefit. Another benefit is that the thinner oil is better at startup where the majority of wear occurs. Looking at the above data 10 C cooler (140 C) is much thicker HTHS and therefore no penalty.)
aehaas
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