Gulf Competition 0w30

[Quattro Pete]

Originally Posted By: dparm
Agreed. But they say its additives meet A3/B4 so that points to HTHS >= 3.5.

Well, I would think that additives is one thing, HT/HS is another.

 

[dparm]

All the oils incorporate a top-of-the-range additive system which, in other products, attains the high international specifications such as ACEA A3/B4 and API SL/CF.


(no formal specifications can be claimed, but these oils contain performance additives designed to achieve ACEA A3/B4 and API SL/CF)



Whatever that means. I sent another email requesting the HTHS and NOACK values.

 

[CATERHAM]

Shear resistance has some academic interest but in the final analysis it is of little importance.
Of the half dozen oils mentioned I'd prefer Mobil 1 0W-40 to all of them for it's higher VI. The fact that it may shear somewhat is an acceptable trade-off for better cold pumping even at room temperature to the lot of them.
A more important question to me is not how much an oil may shear but rather how much of it's initial VI is retained in service.
When you become familiar with any oil it's operational viscosity in service is well known. Besides there are other reasons for viscosity loss, the big one being fuel dilution.
That's why having a oil pressure gauge is so vital to those that like to know what is actually going on with the condition of the oil in an operating engine.

IMO it's a newbie concern to fret about oil shear and it goes on a lot here at BITOG primarily because most cars don't have OP gauges so one really has no idea about what's going on with the
oil in their engines. The viscosity loss could be of concern or of no concern as is likely the case when you're using the spec'd oil.
I find it so funny that some members main oil concerned is that they "just want an oil that stays in grade" based on it's kinematic viscosity in a used oil analysis.

 

[dparm]

I'm not fretting about it at all. I think we've proven here time and time again that most engines will outlast the cars they're put into. By 200k there are 50,000 other things that will be having issues versus a motor that saw regular changes with even a mediocre oil.

This oil caught my attention merely because it is quite thin yet may offer immense film strength. I rather like my Motul 300V anyways.

 

[A_Harman]

Originally Posted By: dparm
I had to estimate the Redline 5w30 density. Their tech is going to get back to me with it, so the shear resistance might change slightly. It's amazing to see the GC shear resistance so high for an off-the-shelf oil.

What's weird is that the other grades of the Gulf Competition are not even close on shear resistance. The 5w40 is like 0.75 or something. Makes me wonder if that shear resistance formula is valid.


When I did those calculations for Redline oils, I used the value of .91 off of their MSDS. I found it hard to believe that all of their oils would have exactly the same density. I got a value of 1.03 for their 5w30. This was the first oil I had looked at for which the HTHS/DV150 ratio went above 1.0.

 

[dparm]

Redline's tech said both 5w30 and 5w40 both have densities of 0.9. But even when I estimated based on other 5w30s, it was still above 1.0.

I too have not seen one go over 1.0. Closest was Motul 300V 5w30 at 0.9882.

Perhaps that formula is not as useful for high-end boutique oils like that?

 

[A_Harman]

Originally Posted By: Quattro Pete
HT/HS of 3.5 out of such thin 0w30 grade? That would be a first, if it in fact were proven to be true.



Not really. German Castrol meets ACEA A3/B3/B4, which means it has HTHS of at least 3.5. The consensus opinion on BITOG is that it has HTHS of 3.6.

 

[dparm]

Pete's point is that the Gulf 0w30 is extremely light for a 30-weight, whereas GC is very heavy for a 30-weight.

Remember that the lower bound for a 30 is 9.3, and the max is 12.49. The Gulf stuff is almost a heavy 20. GC is 12.2, almost a light 40.

 

[Quattro Pete]

Originally Posted By: dparm
Pete's point is that the Gulf 0w30 is extremely light for a 30-weight, whereas GC is very heavy for a 30-weight.

Remember that the lower bound for a 30 is 9.3, and the max is 12.49. The Gulf stuff is almost a heavy 20. GC is 12.2, almost a light 40.

Yup. That's exactly what I meant. Thanks.

 

[A_Harman]

Originally Posted By: CATERHAM
The viscosity loss could be of concern or of no concern as is likely the case when you're using the spec'd oil.
I find it so funny that some members main oil concerned is that they "just want an oil that stays in grade" based on it's kinematic viscosity in a used oil analysis.


Having an oil that stays in grade is something that is supposedly guaranteed by qualifying for the API starburst and donut. But we all know by looking at used oil analysis that oils shear down in grade all the time, and without experiencing fuel dilution. Perhaps API's shear stability test is not a good predictor of behavior in the field?

 

[A_Harman]

Originally Posted By: Quattro Pete
Originally Posted By: dparm
Pete's point is that the Gulf 0w30 is extremely light for a 30-weight, whereas GC is very heavy for a 30-weight.

Remember that the lower bound for a 30 is 9.3, and the max is 12.49. The Gulf stuff is almost a heavy 20. GC is 12.2, almost a light 40.

Yup. That's exactly what I meant. Thanks.


Yep, sorry. I missed the significance of his qualifier "thin" when placed next to 30-weight.

 

[A_Harman]

Originally Posted By: dparm
Redline's tech said both 5w30 and 5w40 both have densities of 0.9. But even when I estimated based on other 5w30s, it was still above 1.0.

I too have not seen one go over 1.0. Closest was Motul 300V 5w30 at 0.9882.

Perhaps that formula is not as useful for high-end boutique oils like that?


So far it seems that the oils that are predominantly ester-based get close to 1.0.
I did the calculation for AMSOIL DEO 5w40 and got .852, which is almost identical to Mobil 1 Turbo Diesel Truck, and actually less than for Shell RT6. It doesn't seem to be a boutique oil thing.

I'm not using the "shear stability" calculation as the be-all and end-all for choosing an oil, but as another piece of data to round out the picture. For me, HTHS leads the way, and the shear stability number gives an indication of how well the oil may maintain its viscosity over time. If two oils have the same HTHS, but one has a higher HTHS/DV150, that would help tip the scales.

 

[CATERHAM]

Originally Posted By: A_Harman
Originally Posted By: Quattro Pete
Originally Posted By: dparm
Pete's point is that the Gulf 0w30 is extremely light for a 30-weight, whereas GC is very heavy for a 30-weight.

Remember that the lower bound for a 30 is 9.3, and the max is 12.49. The Gulf stuff is almost a heavy 20. GC is 12.2, almost a light 40.

Yup. That's exactly what I meant. Thanks.

The significance of the low KV100 spec' of 9.6cSt says more about it's chemistry than how think or thin it is.
Assuming it does have a HTHS vis of 3.5cP it will as "thick" as GC if not thicker due to it's lower VI. As a reminder it is HTHS vis that determines how think or thin an oil is at operating temp's not the KV100 spec'.

A_Harman, I believe GC has a HTHS of 3.5cP and not 3.6cP. My reason for thinking this is because Castrol Edge 0W-40 which has a KV100 spec' of 12.8cSt and HTHS vis of 3.6cP. European Edge 0w30 has the same kinematic spec's as our GC, they don't provide a HTHS vis' but it must be lighter than their 0W-40.

Yep, sorry. I missed the significance of his qualifier "thin" when placed next to 30-weight.

 

[Quattro Pete]

Originally Posted By: CATERHAM
The significance of the low KV100 spec' of 9.6cSt says more about it's chemistry than how think or thin it is.
Assuming it does have a HTHS vis of 3.5cP it will as "thick" as GC if not thicker due to it's lower VI. As a reminder it is HTHS vis that determines how think or thin an oil is at operating temp's not the KV100 spec'.

All I was saying is that I've never seen a 0w30 oil with HT/HS of at least 3.5 yet having a 100 deg KV of only 9.6. Not to say that such oil doesn't exist...

 

[CATERHAM]

Originally Posted By: CATERHAM
Originally Posted By: A_Harman
Originally Posted By: Quattro Pete
Originally Posted By: dparm
Pete's point is that the Gulf 0w30 is extremely light for a 30-weight, whereas GC is very heavy for a 30-weight.

Remember that the lower bound for a 30 is 9.3, and the max is 12.49. The Gulf stuff is almost a heavy 20. GC is 12.2, almost a light 40.

Yup. That's exactly what I meant. Thanks.

The significance of the low KV100 spec' of 9.6cSt says more about it's chemistry than how think or thin it is.
Assuming it does have a HTHS vis of 3.5cP it will as "thick" as GC if not thicker due to it's lower VI. As a reminder it is HTHS vis that determines how think or thin an oil is at operating temp's not the KV100 spec'.
A_Harman, I believe GC has a HTHS of 3.5cP and not 3.6cP. My reason for thinking this is because Castrol Edge 0W-40 which has a KV100 spec' of 12.8cSt and HTHS vis of 3.6cP. European Edge 0w30 has the same kinematic spec's as our GC, they don't provide a HTHS vis' but it must be lighter than their 0W-40.
Yep, sorry. I missed the significance of his qualifier "thin" when placed next to 30-weight.

The significance of the KV100 spec' of 9.6cSt says more about it's chemistry than how thick or thin it is.
Assuming it does have a HTHS vis' of 3.5cP it will be as thick as GC at operating temp's if not slightly thicker due to it's lower VI. As a reminder it is HTHS vis' that determines how thick or thin an oil is at operating temp's not he KV100 spec'.

A_Harman, I believe GC has a HTHS of 3.5cP and not 3.6cP. My reason for thinking this is because Castrol Edge 0W-40 has a KV100 spec' of 12.8cSt and HTHS vis' of 3.6cP. European Edge 0w30 has the same kinematic vis' spec's as our GC, they don't provide a HTHS vis' but it must be lighter than their 0W-40.

 

[dparm]

I guess it depends on what their test consists of. I'm betting it's something generic in a simple motor. A high-performance engine that is particularly hard on oil (which the Gulf oil is targeted at) probably gets very little practical use out of such a test.

It's hard to make a very light oil stay in grade, though. The Gulf stuff has almost no room to shear in order for it to become a 20-weight, whereas GC has a ton.

 

[CATERHAM]

Originally Posted By: Quattro Pete
Originally Posted By: CATERHAM
The significance of the low KV100 spec' of 9.6cSt says more about it's chemistry than how think or thin it is.
Assuming it does have a HTHS vis of 3.5cP it will as "thick" as GC if not thicker due to it's lower VI. As a reminder it is HTHS vis that determines how think or thin an oil is at operating temp's not the KV100 spec'.

All I was saying is that I've never seen a 0w30 oil with HT/HS of at least 3.5 yet having a 100 deg KV of only 9.6. Not to say that such oil doesn't exist...

I didn't think you were questioning the oils existence (perhaps the validity of the spec's and I don't blame you) but rather your reference to it being such a thin 0W-30.

Gulf's spec's theoretically could be correct.
RL's 5W-20 has a similar HTHS/KV100 relationship at 3.3cP/9.1cSt but that's acheived with a lower VI. So yes I think some healthy skepticism is in order here regarding the Gulf oil. At the very least I'd put the HTHS vis as low as possible; say 3.451cP and the KV100 spec' at 9.65cSt to help explain it.

 

[CATERHAM]

Originally Posted By: dparm

It's hard to make a very light oil stay in grade, though. The Gulf stuff has almost no room to shear in order for it to become a 20-weight, whereas GC has a ton.

But that's not the point.
With those vis spec's there is no possibility of VIIs in this oil and therefore shear is not an issue just like it is not an issue with RL.

 

[dparm]

Well what do you mean that shear is "not an issue"? The oil is going to shear, but not much.

 

[A_Harman]

Originally Posted By: CATERHAM
Originally Posted By: dparm

It's hard to make a very light oil stay in grade, though. The Gulf stuff has almost no room to shear in order for it to become a 20-weight, whereas GC has a ton.

But that's not the point.
With those vis spec's there is no possibility of VIIs in this oil and therefore shear is not an issue just like it is not an issue with RL.


I think the low KV is an indication of Gulf's confidence of the ability of the oil to stay in grade. Since the KV100 is only ~3% above the min limit for remaining a 30-weight they have not left a lot of room for decrease. Or are ACEA's specs for shear stability different than API's?