Why would you ever want to run 10W-30 over 5W-30?

[Revving2Redline]

How does 10W-30 stand against 5W-40?

Depends, on a Wal-Mart shelf style synthetic oil I bet 10w30 doesn't shear as much. Its kinda apples to oranges; in a boutique brand I bet they are right on par with each other or at least not night and day

 

[Black Thunder]

Years ago in my teens 10w30 was cheaper than 5w30.

I would imagine some ran it mainly to save money, before the gap cost closed

I really only use it in the summer in my car etc because I got it on clearance or I run it in lawnmowers

 

[tblt44]

My mind the 10w is better I warm climate, less modifiers

 

[4WD]

My mind the 10w is better I warm climate, less modifiers

I just switched to 10W30 - but the EP thinking that drives a little better base stocks - not hard to blend a low mileage 10W

 

[OilUzer]

In general, I like 10W-30 over 5W-30 as long as it meets the winter (cold temp) rating. Less vm and lower Noack # but the only way to be sure about an oil and to compare is the approvals or having additional approvals ... because they can tweak the formulas and the blend left and right.

10W-30's can be formulated with inferior (or less superior) base oil and typically don't come or aren't labeled with any fancy approvals that I can recall so relatively speaking, there is a potential risk. I don't know if I want to call it a real risk since I have had many old cars doing very well on 10W-40 dino! I guess it slowly evolved into a risk after joining bitog.

To avoid the 10W "risk", the only pricey oil that I buy without Euro approvals are M1 EP 10W-30 (my favorite oil) and Valvoline EP 5W-30. Also for couple of old cars and OPEs, I buy Kirkland 5W-30 which comes with "it's cheap" approval.

I've been buying bunch of Castrol lately on sale for $24.xx / 5 qt. Price per performance is pretty good:

Castrol Edge Euro A3/B4 5W-30
API SL
Jug says "Exceeds API SL".

Approved & Licensed Specifications:

• ACEA A3/B4
• BMW LL-01
• MB 229.5
• VW 502 00 / 505 00

Suitable for use in the following specification: MB 229.3

I buy some M1 Euro 0W-40 with bunch of approvals (including A40) or Castrol Euro 0W-40 when on sale. I try to stay away from a wide spread oil but can't help it when they go on sale and have a bunch of Euro approvals. Lol

Basically the only 10W for me is M1 EP 10W-30 currently running in my Tundra. In older days, you could risk getting a dino (conventional) in a 10W but 5W's were a notch higher or at least a syn-blend I think.

 

[OilUzer]

...
viscosity modifiers are added to make oil less thin than they would be when hot. Strip the viscosity modifier from a 5W-40 and you likely end up with a 0W-20.
...

I've been reading some of the previous pages of this thread and your post on page 1 caught my attention.

Can you please elaborate on how does stripping away vm from a 5W-30 will result in a more superior base oil?
Unless if you had started with a more superior base oil. No?
And I thought that would be rare or economically not viable or as viable.

Like I said in my previous post, as a consumer, I don't chase base oil or formulations. only specs, standards and approvals. They can tweak all they want ... But in general, wouldn't you start with a more inferior or less superior (lower grp #) base oil for a 5W?

 

[Jetronic]

I've been reading some of the previous pages of this thread and your post on page 1 caught my attention.

Can you please elaborate on how does stripping away vm from a 5W-30 will result in a more superior base oil?
Unless if you had started with a more superior base oil. No?
And I thought that would be rare or economically not viable or as viable.

Like I said in my previous post, as a consumer, I don't chase base oil or formulations. only specs, standards and approvals. They can tweak all they want ... But in general, wouldn't you start with a less inferior (lower grp #) base oil for a 5W?

I made a few posts on that first page it seems.

If you want to blend a 10W-30 without VM, you have to use superior base oils to what you need to make a 5W-30 with VM. So yes, you have to start with superior base oils. It is rare, but 10W-30 synthetics do exist in various forms, from on the shelf to boutique oils.

If you go by approvals, you exclude a lot of these oils, as the manufacturer approvals are always limited to a few viscosity grades.

If you want to make a 5W-XX oil, you don't need very expensive base oils, just thin grp II and grp III, viscosity boosted by VM. That is if you don't care much about volatility, shear stability, cleanliness and that is what manufacturer aprovals are trying to move people away from: the cheapest possible formulations.

 

[Thebigm]

I've always wondered this and never have figured it out.

Assuming you keep your RPMs below 2,500 until the car warms up, what would the point in running 10W-30 over 5W-30? If anything I would think you would want to run 5W-30 over the other to get oil to the valvetrain faster.

When up to operating temps when you would go wide open throttle, both oils are the same weight.

Less shear

 

[buster]

If you knew for certain that the 10w-30 had less VII than the 5w30 would be the number one reason to use a 10w-30.

 

[Patman]

If you knew for certain that the 10w-30 had less VII than the 5w30 would be the number one reason to use a 10w-30.

The only way I would be comfortable going with a 10w30 would be if it were made by Amsoil or HPL. Then I’d know it was made with little to no VII

 

[OilUzer]

I made a few posts on that first page it seems.

If you want to blend a 10W-30 without VM, you have to use superior base oils to what you need to make a 5W-30 with VM. So yes, you have to start with superior base oils. It is rare, but 10W-30 synthetics do exist in various forms, from on the shelf to boutique oils.

If you go by approvals, you exclude a lot of these oils, as the manufacturer approvals are always limited to a few viscosity grades.

If you want to make a 5W-XX oil, you don't need very expensive base oils, just thin grp II and grp III, viscosity boosted by VM. That is if you don't care much about volatility, shear stability, cleanliness and that is what manufacturer aprovals are trying to move people away from: the cheapest possible formulations.

Thanks for the response but your statement below was the one that got me curious:

"Strip the viscosity modifier from a 5W-40 and you likely end up with a 0W-20. "

I can see removing or reducing the vm resulting in a lower SAE viscosity grade (e.g. From 40 to 30 or 20) but turning it into a more superior base oil required for a 0W was my question. Unless the oil started with a superior base oil to begin with. Which is not economically viable for a 5W oil. No?

 

[Randy_R]

10W-30 is a little thicker/heavier/viscous? My Saturn is a leaker. I’ll go back to 5W-30 in the fall. Maxlife/high mileage of course.

 

[Jetronic]

Thanks for the response but your statement below was the one that got me curious:

"Strip the viscosity modifier from a 5W-40 and you likely end up with a 0W-20. "

I can see removing or reducing the vm resulting in a lower SAE viscosity grade (e.g. From 40 to 30 or 20) but turning it into a more superior base oil required for a 0W was my question. Unless the oil started with a superior base oil to begin with. Which is not economically viable for a 5W oil. No?

5w-40 with a slew of mfr approvals, like mb 229.5. The base oil part will be very similar to 0w-20. Maybe some will end up as 5W-20 though.

 

[kschachn]

10W-30 is a little thicker/heavier/viscous? My Saturn is a leaker. I’ll go back to 5W-30 in the fall. Maxlife/high mileage of course.

Depends on the particular oil and more importantly on the temperature.

 

[JohnnyJohnson]

Yes I have some Havoline Pro DS 10W-30 I think I will run in the Mazda this summer.

 

[ChrisD46]

All else being equal

the 10W-30 has less viscosity modifiers which are not 100% shear stable and cause deposits
the 10W-30 is less volatile
the 10W-30 has a higher base oil viscosity mix, which timing chains love.

If you can get a synthetic 10W-30 and the temperatures in your area are high enough to use it (above 0°F at all times), I see no reason to use 5W-30

I wonder what the major oil companies chemical make up of synthetic 10W30 vs. their 5W30 oils are ? Do their synthetic 5W30 oils get better ingredients , add packs , base stocks , etc. than the 10W30 synthetic oils ? If so , then even if your temps stay above 0 degrees F , you might be better off running a 5W30 oil .

 

[OVERKILL]

I wonder what the major oil companies chemical make up of synthetic 10W30 vs. their 5W30 oils are ? Do their synthetic 5W30 oils get better ingredients , add packs , base stocks , etc. than the 10W30 synthetic oils ? If so , then even if your temps stay above 0 degrees F , you might be better off running a 5W30 oil .

As I've posted previously, Mobil has shown that a 10W-30 can be blended with their EHC (Group II) bases, and since there are very few OE approvals that apply to a 10W-30, they are very much an "also made" product, which means that, outside of boutique blender applications, you likely aren't seeing best effort formulations in this grade.

 

[Olds394]

That may be the trend for certain brands of oils with a "no holds barred" formulation approach, but if we are talking your Walmart shelf offering, as the blending guide examples I provided earlier show, you can't just make that assumption. A 10W-30 isn't eligible for dexos or many other OE specs so there's no real incentive to make it "better" than a 5W-30 that is dexos and carries approvals.

This Havoline conventional 10W-30 for example, certainly isn't anything to write home about:
View attachment 255653

Heck, neither was this Royal Purple 10W-30:
View attachment 255654

And of course then we have 5W-30's with no VII in them, like those found in HPL's No VII series.

Link to this site?

 

[OVERKILL]

Link to this site?

The HPL site?

 

[4WD]

As I've posted previously, Mobil has shown that a 10W-30 can be blended with their EHC (Group II) bases, and since there are very few OE approvals that apply to a 10W-30, they are very much an "also made" product, which means that, outside of boutique blender applications, you likely aren't seeing best effort formulations in this grade.

There are over two dozen EHC customers including big name and - I’ll stop there before folks get wound up …