5W-30 VS. 10W-30

[jonnied1]

Looking at the Mobil 1 High Mileage synthetic oil. Which weight oil will provide the best protection in OPE under heavy loads in moderate temps (70 to 90 deg.). I've read that the 5W-30 will shear less than the 10W-30. Fact or not? Am I off my rocker on this?
Thanks.

 

[CT8]

Either will work with possible the 10W-30 being better due the the wee bit thicker 10w part to possible reduce the oil consumption. what have you read about the sheering difference?

 

[Doog]

What vehicle, engine, driving service, OCI?...sorry OPE...........Rotella 10w30 would be my choice.

 

[barkingspider]

Both are the same above zero degrees.

 

[umungus1122]

10w-30 M1 HM for 70-90 degrees.

 

[BrocLuno]

Have to look at the HTHS or viscosity at 100*C of each to determine. Air-cooled motors (making assumption here) can get hot spots that can toast weak oils. M1 is not really weak, but one is less able than the other. The question is which have more Group III and maybe Group IV ... The formula is not the same ...

I'm guessing the 5W-30 may be the more robust oil ...

But, if it were my equipment, it'd be Rotella T6 5W-40. It's a bit on the thin side for a 40 at op temp, so more like a 35. But runs real well in OPE stuff I have

 

[Eosyn]

I use Quaker State Ultimate Durabilty 10W30 because it has the lowest NOACK at the most affordable price.

This chart helped me make that decision. Note: the grade used in the chart is 5W30 but my manual said to use 10W30. I assumed the NOACK for the 10W30 to be similar to the 5W30.

 

[UltrafanUK]

In general terms the 10w30 will use less VI additives than the 5w30. The VI weaken the molecular structure slightly, so the 10w30 can be more shear resistant.

 

[SR5]

Originally Posted By: jonnied1
I've read that the 5W-30 will shear less than the 10W-30. Fact or not?


Should be the other way, all things being equal (oil and VII chemistry), the 10W-30 should shear less as it has less VII polymers in it.

Also 10W30 tends to have a lower Noack volatility due to heavier base oil in the mix. For example Sinclair Full Synthetic, the 5W30 has a Noack of 11.1% while the 10W30 has a Noack of 6.2% and is a lot less volatile.

The M1 HM oils are great. They produce stronger/thicker oil films and have more zinc (ZDDP) anti-wear agents.
Regular M1 5W30 has a HTHS of 3.1 and has 900 ppm Zinc
M1 5W30 HM has a HTHS of 3.3 and has 1100 ppm Zinc
M1 10W30 HM has a HTHS of 3.5 and has 1100 ppm Zinc

I like high HTHS & Zinc, but low Noack. M1 10W30 HM hits that nail on the head.

A 10W oil is good down to 0F (-18C), and only if starting at temperatures below that would I consider a 5W oil.

 

[cmhj]

Typically 10-30 will shear less

 

[umungus1122]

http://www.mobil.com/english-US/Passenger-Vehicle-Lube/pds/NAXXMobil-1-High-Mileage-Oil

As most mentioned, the 10w-30 should have a lower NOACK, and it has a higher HTHS. A3/B3.

 

[NibbanaBanana]

Probably the most important thing is to go by what the manual says. I use M1 10w-30 in all my OPE except snowblower where I use M1 5w-30. The Tecumseh snowblower engine manual says to use 5w-30 preferred, or 10w-30. It says in bold capital letters "DO NOT USE 10W-40 OIL". Don't know why, but I'm not going to use 10W-40 oil in it.

 

[kschachn]

Originally Posted By: NibbanaBanana
Probably the most important thing is to go by what the manual says. I use M1 10w-30 in all my OPE except snowblower where I use M1 5w-30. The Tecumseh snowblower engine manual says to use 5w-30 preferred, or 10w-30. It says in bold capital letters "DO NOT USE 10W-40 OIL". Don't know why, but I'm not going to use 10W-40 oil in it.


Most likely an artifact of when wide viscosity spread oils were inferior to what they are today. This has come up a lot here on Bitog lately. A good, modern 10W-40 isn't going to be detrimental to that engine. Especially if it is M1 HM 10W-40 which carries ACEA A3/B3.

But why you would run a 10W-40 in a snow thrower is another question, especially if you are starting it at temperatures below zero.

 

[kschachn]

Originally Posted By: UltrafanUK
In general terms the 10w30 will use less VI additives than the 5w30. The VI weaken the molecular structure slightly, so the 10w30 can be more shear resistant.


Weakens the molecular structure of what?

 

[JTK]

Originally Posted By: jonnied1
Looking at the Mobil 1 High Mileage synthetic oil. Which weight oil will provide the best protection in OPE under heavy loads in moderate temps (70 to 90 deg.). I've read that the 5W-30 will shear less than the 10W-30. Fact or not? Am I off my rocker on this?
Thanks.


Either would be a great oil. Like others have mentioned, theoretically, 10w30 would contain less viscosity improvers, etc, but any concerns caused by this would be tough to quantify.

I personally see no need or value in 10w30 with the 5w30s we have available today.

 

[jonnied1]

Ok, here is one for you guys:
Viscosity index (VI) is an arbitrary measure for the change of viscosity with variations in temperature. The lower the VI, the greater the change of viscosity of the oil with temperature and vice versa. It is used to characterize viscosity changes with relation to temperature in lubricating oil.

Here is the VI Index from the Mobil site for the M1 High Mileage oil:
Viscosity Index
5W-20 5W-30 10W-30 10W-40
150 165 149 160
Notice the 5W-30 is the highest. Is this an important factor in air cooled engines used in OPE at moderate temps?

 

[passgas55]

I would go with the M1 HM 10/30. This oil can take care of all my gasoline engines my Z4, chevy 1500 to all my air cool engines. I use delo 15/40 for my tractor and 4 wheeler. Makes things simple for me.

 

[UltrafanUK]

Originally Posted By: JTK
Originally Posted By: jonnied1
Looking at the Mobil 1 High Mileage synthetic oil. Which weight oil will provide the best protection in OPE under heavy loads in moderate temps (70 to 90 deg.). I've read that the 5W-30 will shear less than the 10W-30. Fact or not? Am I off my rocker on this?
Thanks.


Either would be a great oil. Like others have mentioned, theoretically, 10w30 would contain less viscosity improvers, etc, but any concerns caused by this would be tough to quantify.

I personally see no need or value in 10w30 with the 5w30s we have available today.


They make better long life oils, for example Liqui Moly Synthoil 10w30 is about as good as it gets if you need a 30 grade and want to do extended OCI's. I would not say the same about non German (Group 4) full synthetics, so you do need to compare like with like in base stock terms.