Mobil 1 HM 10W-30 Pour Point

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I find it interesting that among all of the Mobil 1 products for which a pour point is listed on a product data sheet, the HM 10W-30 has the lowest of the bunch at -54 degrees Celsius. This despite the relatively high HTHS of 3.66. This pour point is lower than their M1 5W-20 and even lower than the vaunted SSO. I have been using it in my 1996 Camry (140k) right through the winter and have been very pleased. Literally zero drop in oil level on the dipstick over the course of two 5k oci's.
 
I know another person that said the same thing about this oil regarding volatility. It's a really overlooked oil. Great for an out of warranty LS series engine.
 
I am not sure of the relatioship between pour point and pumpability. I always check the cSt of any oil that I consider for use, and I check it at 0F and 230F. The M1 5W-30 has a 0F cSt of 2054. The HM 10W-30 has a 0F cSt of 3858. That is 1804 higher than the 5W-30 and it would be thicker/harder to pump than the 5W-30. You would have to be at 12F to get the same pumpability of the 5W-30 at 0F. However, all the other advantages of the 10W-30 HM may be more important to your situation than pumpability. For the last 18 years, I have used an oil with a 0F cSt of 6700!!

The M1 High Mileage 10W-30/40 are really great heavy duty oils as well as high mileage oils.
 
I too am not sure of the precise relationship between pour point and pumpability. However, I still find it rather intriguing that the HM 10W-30 has the one of the lowest pour points out there. I would certainly be interested in knowing why this is the case. Pour point is clearly a relevant measurement for cold weather performance. Otherwise, why would most manufacturers bother to measure and publish it. On paper this particular M1 oil strikes me as quite impressive. Out of curiosity, where did you obtain the cSt numbers for 0F and 230F? Mobil only publishes for 40C and 100C.
 
Pumpability is a dynamic viscosity (Poise) rather than kinematic viscosity (Stokes) thing.

cSt is how fast an oil drop spreads out, how viscous it is sitting there.

cP is the resistance of oil to flow which is used for the cold testing which is the W grade portion of oil.

A 10W oil has the same pumpability as a 10W oil with set limits for each grade, a 5W oil is automatically better than a 10W oil.

Pour point is the point at which it no longer flows as one contiguous fluid when poured, it globs rather than pours. More related to kinematic than dynamic viscosity.
 
Don't know why that got away from me. You can run any one oil by putting 100% to the right of the oil. You can also check on up to 3 oils blended together. Just make sure your percentages equal 100. I change the tempereature setting at the bottom from C to F and can check any oil temp I desire. You can also work it by supposition which is how I came up with an oil I am getting blended for my truck.

This was posted by Gary Allan, one of the Amsoil dealers. It is much easier than my calculator, even a programmable calculator.
 
Originally Posted By: MGregoir
A 10W oil has the same pumpability as a 10W oil with set limits for each grade, a 5W oil is automatically better than a 10W oil.
So does this mean that a 5W dino will always flow better than a 10W synthetic down to their respective pour points.
 
Originally Posted By: FrankN4

The M1 High Mileage 10W-30/40 are really great heavy duty oils as well as high mileage oils.


That means there is a 30wt synthetic Rotella T!
 
Originally Posted By: BerndV
Originally Posted By: MGregoir
A 10W oil has the same pumpability as a 10W oil with set limits for each grade, a 5W oil is automatically better than a 10W oil.
So does this mean that a 5W dino will always flow better than a 10W synthetic down to their respective pour points.


Assuming things are somewhat linear.

10W oils are rated for cold cranking at -25, and pumpability at -30.

5W oils are rated for cold cranking at -30 and pumpability at -35.

The pumpability limit is 60,000 cP (although few oils breach that). That is also called limit pumping viscosity.

The bare minimum standard 5W-30 will be 6600 cP cranking at -30, where the bare minimum standard will be 7000 cP at -25. 0W oils are 6200 at -40, so the standard becomes stronger with each temperature range, and because viscosity is somewhat logarithmic, a 5W oil's cold performance will always beat the 10W oil's, and the lower the temperature the greater the gap will increase. If the 10W oil were as good as the 5W oil, it would be rated as a 5W oil, simply put.

The 10W synthetic may still pour. The points where this becomes significant are in conditions few see, which would be starts with no block heaters at -30 Celsius or lower.
 
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MGregoir

My 08 Chevrolet truck calls for a 5W-30 which meets GM 6094M standards. I looked that 6094M up and it means that it has a cP of 6000. Is it still rated a 5W rather than a 0W because it is measured/tested at -30 rather than -40?

I have read on here, and in other places, that a synthetic may, for example, be an actual 30 grade but meet 10W grade specifications/requirements. In simple terms, does that actually mean that it requires few or no viscosity index improvers over a wider range of use because of the character of the synthetic base fluid?


jorton

If you go to the M1 web site, you will see that the M1 high mileage oils have much greater sheer stability than their regular oils, 1000 ZDDP, extra antioxidents, extra detergents, and extra seal conditioners. They are also on the higher end of the cSt velocity range. Not just a regular oil with extra detergents and extra seal conditioners, they are complete oils unto themselves.
 
The 6094M is requirements set out for pumpability more than cranking. If your manual says you can use 10W-30 above 0 F, then you are fine. The ratings are based on the temperature and dynamic viscosity test results. It is a pretty basic test and almost all 0W-20, 0W-30 5W-20, 5W-30 and 10W-30 on the market rated SM/GF-4 pass.

Amsoil makes ACD which is a very high viscosity index straight 30, as in there are no viscosity improvers added, but because the base fluids are so good it passes the 10W tests to be rated as a multi grade, making it suitable for both types of application.
 
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