Is 10W-30 really obsolete?

[edhackett]

Show me a 5W-30 that has a higher HTHS, lower NOACK, and will shear less than the 10W counterpart that is formulated with higher viscosity base stocks. These must be from the same product line, top synthetics included

Higher HTHS, lower NOACK, and better shear resistance are all attributes that I value in an oil. This holds especially true as we move to DI engines tuned for U.S. emission standards.

Ed

 

[friendly_jacek]

Of course it's not obsolete where viscosity stability is needed.

 

[440Magnum]

Completely obsolete. "Where viscosity stability is needed??" That's pretty much why its obsolete. It has less viscosity stability than a 5w30, and less still than a 0w30 or 0w40.

 

[mechanicx]

I wouldn't say 10W30 is obsolete at all being SN oil. But SN 5W30 seems to be blended to the same Noack ~13, HTHS and as far as I know the same sheer stability. In a warm climate or during Summer there's no reason to not use 10W30, but there doesn't seem to be any reason to not use 5W30 either.

In the heat in parts of Nevada you should be able to even run a single grade 30 like Pennzoil HD and I bet a few people still do that. It should have a low Noack and be very sheer stable. Being SM or SN it is probably a group II with very little if any VII.

 

[CATERHAM]

10W-30 is a dino grade and in that regard it is not obsolete.
But when it comes synthetic oils, since you can acheive an acceptably low NOACK percentage in 5W and 0W oil formulations while using lighter but much higher VI base oil stocks the 10W-30 grade has been rendered largely obsolete.

When comparing any two oils regardless of the grade, they should have the same HTHSV, that is the true measure of how thick or thin the oils will be at normal operating temp's. Heavier, higher HTHSV oils of the same chemistry will have a lower NOACK %. To acheive a high VI 0W/5W-30 oil you are using lighter base oil stocks which will have somewhat higher NOACK values, so there is that trade off unless you also upgrade the base oil quality; say going from GP III to GPIII+ or even blending in some GP IV or GP V oils.

The point is, when it comes to synthetic oils you don't have to settle for a low VI 10W-30, 10W-40 or even 10W-50. There are high VI, low NOACK 0W and 5W oils in all these grades.

 

[HTSS_TR]

Originally Posted By: CATERHAM
10W-30 is a dino grade and in that regard it is not obsolete.
But when it comes synthetic oils, since you can acheive an acceptably low NOACK percentage in 5W and 0W oil formulations while using lighter but much higher VI base oil stocks the 10W-30 grade has been rendered largely obsolete.

When comparing any two oils regardless of the grade, they should have the same HTHSV, that is the true measure of how thick or thin the oils will be at normal operating temp's. Heavier, higher HTHSV oils of the same chemistry will have a lower NOACK %. To acheive a high VI 0W/5W-30 oil you are using lighter base oil stocks which will have somewhat higher NOACK values, so there is that trade off unless you also upgrade the base oil quality; say going from GP III to GPIII+ or even blending in some GP IV or GP V oils.

The point is, when it comes to synthetic oils you don't have to settle for a low VI 10W-30, 10W-40 or even 10W-50. There are high VI, low NOACK 0W and 5W oils in all these grades.

I agree. Dino 10W30 is not obsolete, but synthetic is.

Mobil 1---5W30---10W30

Vis@100ºC-11.0---10.1
Vis@ 40ºC-61.7---63.2
VI---------172---146
HTHS-------3.1---3.0

 

[friendly_jacek]

Originally Posted By: 440Magnum
It has less viscosity stability than a 5w30.


Please explain how 5W30 is more stable than 10W30. We are talking non-synthetic oils here.

 

[CATERHAM]

Originally Posted By: friendly_jacek
Originally Posted By: 440Magnum
It has less viscosity stability than a 5w30.


Please explain how 5W30 is more stable than 10W30. We are talking non-synthetic oils here.

Your right since a dino 10W-30 uses heavier base oil stocks.
But even with minerals oils, due to the use of much higher quality VIIs than were once used, the difference in shear stability has narrowed considerably between a 5W-30 and 10W-30.
The fact that most formulators tend to make their 10W-30 heavier (higher HTHSV) than their 5W-30 is really a separate issue.
Consiquently I still would prefer a 5W-30 dino over a 10W-30. And if I needed a slightly heavier 30wt I'd just add in some higher VI 10W-40.

 

[Solarent]

Caterham, that would require mixing oils - and I don't know anyone that would be comfortable with that....

(please understand my tongue-in-cheek jest here... you are of course one of the most confident custom oil mixers in our little community)

 

[fdcg27]

In the case of M1 at least, HTHS is listed as slightly higher for the 5W-30 than it is for the 10W-30.
Mobil does not give volatility figures for either oil.
WRT shearing, only a seies of UOAs would show that.
I buy 10W-30 only when it comes at a killer price.
If it's priced the same as 5W-30, I'll take the 5W-30 home.
Nothing wrong with 10W-30, and I use it in my cars.
It is no longer my first choice, though.

 

[LeakySeals]

Originally Posted By: CATERHAM
Originally Posted By: friendly_jacek
Originally Posted By: 440Magnum
It has less viscosity stability than a 5w30.


Please explain how 5W30 is more stable than 10W30. We are talking non-synthetic oils here.

Your right since a dino 10W-30 uses heavier base oil stocks.
But even with minerals oils, due to the use of much higher quality VIIs than were once used, the difference in shear stability has narrowed considerably between a 5W-30 and 10W-30.
The fact that most formulators tend to make their 10W-30 heavier (higher HTHSV) than their 5W-30 is really a separate issue.
Consiquently I still would prefer a 5W-30 dino over a 10W-30. And if I needed a slightly heavier 30wt I'd just add in some higher VI 10W-40.


The statement used to be (several years ago):

"VI improvers are not as stable as the base oil they were added to, and have less resistance to oxidation or degradation due to shear than does the base oil. Therefore between two oils with the same VI, the one with the lower VI improver would be more thermally stable and suffer less viscosity loss, all else being equal."

Does that statement suggest that the 10w30 is more stable than a 5w30?

 

[Garak]

Originally Posted By: edhackett
Higher HTHS, lower NOACK, and better shear resistance are all attributes that I value in an oil. This holds especially true as we move to DI engines tuned for U.S. emission standards.


Time will tell. I'm assuming GM came out with the dexos1 specification for more than the royalty fees.

I would suggest some of those issues are important to them.

 

[CATERHAM]

Originally Posted By: LeakySeals
Originally Posted By: CATERHAM
Originally Posted By: friendly_jacek

.

The statement used to be (several years ago):

"VI improvers are not as stable as the base oil they were added to, and have less resistance to oxidation or degradation due to shear than does the base oil. Therefore between two oils with the same VI, the one with the lower VI improver would be more thermally stable and suffer less viscosity loss, all else being equal."

Does that statement suggest that the 10w30 is more stable than a 5w30?

"Therefore between two oils with the same VI"
That quote doesn't apply to your question since the 10W-30 grade has a significantly lower VI than a typical 5W-30.

 

[bluesubie]

I will be switching to obsolete 10W-30 at my next change.

-Dennis

 

[4ever4d]

Maybe not obsolete. Very unnecessary though.

 

[LeakySeals]

Originally Posted By: 4ever4d
Maybe not obsolete. Very unnecessary though.


In a late model car, low miles, perfect world scenario you may come to that conclusion.

 

[4ever4d]

Originally Posted By: LeakySeals
Originally Posted By: 4ever4d
Maybe not obsolete. Very unnecessary though.


In a late model car, low miles, perfect world scenario you may come to that conclusion.

I should express IMO. I am currently using an 5w-30 in one of my vehicles specd for 10w-30 and feel i have lost nothing in the process.

 

[LeakySeals]

Originally Posted By: 4ever4d
Originally Posted By: LeakySeals
Originally Posted By: 4ever4d
Maybe not obsolete. Very unnecessary though.


In a late model car, low miles, perfect world scenario you may come to that conclusion.

I should express IMO. I am currently using an 5w-30 in one of my vehicles specd for 10w-30 and feel i have lost nothing in the process.
Wasn't suggesting 10w30 was better or worse. My response was to the generalization that a 10w30 is very unnecessary. Adding a quart helps me in the summer months with valve seal ailments. Less drip drip drip overnight, less blue smoke at startup. I do think you made the right move thinning if there are no issues.

 

[KCJeep]

For most vehicles 10w30 is no longer necessary, but I find it still to be a very viable and functional option in the warmer months in my older vehicles. I rarely by it anymore unless it's an HDEO or a steal (got a bunch for a song on K-mart clearance) but it still works just fine.

 

[Nickdfresh]

For older vehicles where a slightly thicker oil is desired that doesn't shear down, 10W-30 is certainly not obsolete...