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Founding Member #2 2008 SLK55 AMG
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Discussion Starter #1
This is specific to Mobil1 0W40 but may apply to synthetic oils in general.

How high a temperature can Mobil 1 0W40 withstand and for how long (duration) without losing its effectivity?

I noticed my engine oil temp go up to 127ºC for perhaps 10 minutes while doing a run at Mount Wilson this past weekend, going up to 3rd gear only with the rpm between 3-5.5K rpm. This got me curious if the synthetic oil would "degrade" at that temperature.

Mobil 1 0W40 data sheet states:
HTHS Viscosity, mPa•s @ 150ºC, (ASTM D4683) value is 3.8

Viscosity, cSt (ASTM D445)
@ 40º C, value is 75
@ 100º C, value is 13.5

What does the above mean?
 

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Founding Member #2 2008 SLK55 AMG
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Discussion Starter #3 (Edited)
What do the values mean?

3.8 at 150ºC
75 at 40º C
13.5 at 100º C

Edit: found some explanation:

"High-temperature high-shear-rate (HTHS) viscosity is an indicator of a motor oil's resistance to flow in the narrow spaces between rapidly moving parts in fully warmed up engines. The most common test here is ASTM D4683, which simulates the conditions found in an engine's crankshaft and connecting rod bearings, as well as other narrow regions. This measurement has important implications for such factors as engine fuel economy, valvetrain wear and bearing protection."

ACEA Engine Oil Sequences: gasoline and diesel engine oils

A1/B1 Stable, stay-in-grade oil intended for use at extended drain intervals in gasoline engines and car & light van diesel engines specifically designed to be capable of using low friction low viscosity oils with a high temperature / high shear rate viscosity of 2.6 mPa*s for xW/20 and 2.9 to 3.5 mPa.s for all other viscosity grades. These oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

A3/B3 Stable, stay-in-grade oil intended for use in high performance gasoline engines and car & light van diesel engines and/or for extended drain intervals where specified by the engine manufacturer, and/or for year-round use of low viscosity oils, and/or for severe operating conditions as defined by the engine manufacturer.

A3/B4 Stable, stay-in-grade oil intended for use in high performance gasoline and direct injection diesel engines, but also suitable for applications described under A3/B3.

A5/B5 Stable, stay-in-grade oil intended for use at extended drain intervals in high performance gasoline engines and car & light van diesel engines designed to be capable of using low friction low viscosity oils with a High temperature / High shear rate (HTHS) viscosity of 2.9 to 3.5 mPa.s. These oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.
 

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Once upon a time, I remember during those muscle cars were still on the road I used a straight grade motor oil during the smmer months. so a Mobil 1 with 0w40 viscosity consider a straight grade?
 

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Books have been written on Different types of viscosity.
In this situation viscosity of oil is its resistance to flow.
Oil has to be thin enough to be picked up by the pump and to get to the furthest component that needs it. Also it needs to flow at sufficient quantity to remove heat from these components.
The thinnest oil that will prevent metal to metal contact at maximum load will do the best job.
As long as the oil film is maintained your hotter oil will remove heat the best.
 

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Once upon a time, I remember during those muscle cars were still on the road I used a straight grade motor oil during the smmer months. so a Mobil 1 with 0w40 viscosity consider a straight grade?
With "straight grade" there's only one number. Like 30W (for your lawn mower). Or maybe 50W (for your Offenhauser).

Pretty obsolete stuff.
 

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Eddy -

From what I'm reading here, you're looking at kinematic viscosity measurements.
The lower the number, the faster it flows through the ports inside your engine due to heat.

The higher the number, the slower it travels.

On another note, 60% of your engine cool down is by the fluid in the radiator and that's only on the top half of your engine. The rest is cooled down by your engine oil.

I hope this makes sense.

Enjoy,
Dave
 

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I'd recommend bobistheoilguy site for crazy in-depth oil talk.

I will say this, you are WISE to use the Mobil 1 0w40. It far surpasses requirements of the major European manufacturers.

The Formula M that some dealers use was engineered to just meet Mercedes spec.

On the oil analysis I have ran, the 0w40 Mobil 1 is MUCH richer in protecting additives than the 5w40 Formula M.
 

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I'd recommend bobistheoilguy site for crazy in-depth oil talk.

I will say this, you are WISE to use the Mobil 1 0w40. It far surpasses requirements of the major European manufacturers.

The Formula M that some dealers use was engineered to just meet Mercedes spec.

On the oil analysis I have ran, the 0w40 Mobil 1 is MUCH richer in protecting additives than the 5w40 Formula M.
Not only that, it gives you much faster oil flow at start up, especially at low temperatures.
 

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I'd recommend bobistheoilguy site for crazy in-depth oil talk.
Very good recommendation :tu:

I will say this, you are WISE to use the Mobil 1 0w40. It far surpasses requirements of the major European manufacturers.

The Formula M that some dealers use was engineered to just meet Mercedes spec.

On the oil analysis I have ran, the 0w40 Mobil 1 is MUCH richer in protecting additives than the 5w40 Formula M.
Castrol Euro Formula 0W-30 is an excellent oil also(and MB 229.5 rated). Don't be fooled by the "30"; it is almost a "40" and also has a fine additive package.

Eddy, have you had an oil analysis done? If not, you might check-out Blackstone Labs( http://www.blackstone-labs.com/ )...if you have, never mind :)
 

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Very good recommendation :tu:



Castrol Euro Formula 0W-30 is an excellent oil also(and MB 229.5 rated). Don't be fooled by the "30"; it is almost a "40" and also has a fine additive package.

Eddy, have you had an oil analysis done? If not, you might check-out Blackstone Labs( http://www.blackstone-labs.com/ )...if you have, never mind :)
I agree...I think I know that oil, and it is good. On paper it doesn't have as many goodies in it than M1 0w40, but there must be hidden things because it performs well in people's cars.

The *only* problem is that for North America, Mercedes tells us to use a 40 weight in anything above something like 80 degrees?

I know the 30w Castrol is very close to a 40, but just by "specs," if still under warranty, one might be careful.
 

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I don’t think it is really about the brand but more about the new generation of oils.
I remember the time the first 10 w … oils came on the marked, after that the first 5W…, now the 0W…
I’m looking forward to the day a lubricant will be developed that will have the same flow characteristic at minus 50 C as at plus 200 C; almost instant perfect lubrication at startup.
 

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Founding Member #2 2008 SLK55 AMG
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Discussion Starter #13
Very good recommendation :tu:



Castrol Euro Formula 0W-30 is an excellent oil also(and MB 229.5 rated). Don't be fooled by the "30"; it is almost a "40" and also has a fine additive package.

Eddy, have you had an oil analysis done? If not, you might check-out Blackstone Labs( http://www.blackstone-labs.com/ )...if you have, never mind :)
Nope, no oil analysis but have read on other forums specifically with the SLK and the oil analysis was excellent. The comment that struck me was that the oil analysis lab stated it seems the engine was assembled by technicians as if they were wearing white lint free gloves.
 

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Not only that, it gives you much faster oil flow at start up, especially at low temperatures.
FWIW, once upon a time I looked up cold pour points on Mobil's website and they were exactly the same for 0W, 5W, and 10W versions. The 15W-50 was maybe 15 degrees warmer, i.e. about 40 F below.
 

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Hello,

I wonder what elevation were you? I mean I had rev and drove hard at times both with my SLK55 AMG and also the SLK280 during very hot ambient temperatures and never had reached that high a temperature.

Were you driving for like an extended period of time in high revs and low gear? And going up a very long step hill?

Hummmmm.............:confused:




This is specific to Mobil1 0W40 but may apply to synthetic oils in general.

How high a temperature can Mobil 1 0W40 withstand and for how long (duration) without losing its effectivity?

I noticed my engine oil temp go up to 127ºC for perhaps 10 minutes while doing a run at Mount Wilson this past weekend, going up to 3rd gear only with the rpm between 3-5.5K rpm. This got me curious if the synthetic oil would "degrade" at that temperature.

Mobil 1 0W40 data sheet states:
HTHS Viscosity, mPa•s @ 150ºC, (ASTM D4683) value is 3.8

Viscosity, cSt (ASTM D445)
@ 40º C, value is 75
@ 100º C, value is 13.5

What does the above mean?
 

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Above 140 degC some components of the additive package start to breakdown which would considerably shorten the oil-drain interval. The 127 degC you mention should be no problem, it's not uncommon to see 130 degC oil temp on a modern engine. The synthetic PAO base oil material used in Mobil 1 will cope too, no problem.
 

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Nope, no oil analysis but have read on other forums specifically with the SLK and the oil analysis was excellent. The comment that struck me was that the oil analysis lab stated it seems the engine was assembled by technicians as if they were wearing white lint free gloves.
I will be having Blackstone do an analysis very soon. I put Castrol 0W-30 in at 32,283 and it has a little over 3,000 on it now. I'll post the results when ...white lint free gloves as opposed to blue nitrile gloves(per UK-C200 :))? :Beer:
 

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I agree...I think I know that oil, and it is good. On paper it doesn't have as many goodies in it than M1 0w40, but there must be hidden things because it performs well in people's cars.

The *only* problem is that for North America, Mercedes tells us to use a 40 weight in anything above something like 80 degrees?

I know the 30w Castrol is very close to a 40, but just by "specs," if still under warranty, one might be careful.
Looking in my "Factory Approved Service Products" booklet, all of the oil "weights" are "good" to 86*(the graph goes no higher) and only the 0W-30 to 5W-50 are good to -13*. Also, something very interesting from this booklet is this statement; "Select oil viscosity according to the lowest air temp expected before the next oil change using the chart below." Very interesting(in my best Arte Johnson)."
 
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