Joe Gibbs Driven LS30

[A_Harman]

A Joe Gibbs oil formulated specifically for GM LS-series engines that get a lot of track use.

From Polaris Labs
Wear Metals
Should be low for a virgin oil, only 1 ppm each of Iron and Aluminum.

Contaminant Metals
Si: 4 ppm
Na: 3

Multi-Source Metals
None. No Ti, Mo, or B, which are additive metals we've all gotten used to seeing lately.

Additive Metals
Mg: 151
Ca: 2435
P: 983
Zn: 1135

KV100 = 10.9 Cst
TBN = 10.1
Oxidation = 10
Nitration = 5

I'm surprised at how simple the additive package looks.
With ~1000 ppm of Phos, it would qualify as an SL oil.
The main reason I replaced Red Line 5w30 with the Joe Gibbs LS30 was the higher TBN.

 

[CATERHAM]

Phos' level is not excessively high, on par with M1 HM and 0W-40 oils.
I'm sure it's quite shear stable.
As you know the only way to tell how long it will last in service is to try it.

As a point of interest, I had a chat with Lake Speed Jr a couple of years ago about running their XP2 0W-20 which is a very low TBN race dedicated oil in my Caterham and he suggested I could, just change the oil filter every 1,000 miles and top up with fresh oil. The purpose of changing the oil filter was an expedient way of lowering the oil level to top up with fresh oil which maintains a cleaning effect.
Of course I wouldn't entertain such a wasteful practice but I didn't have the heart to tell him so, he was so willing to talk about race oil selection and high stress (racing) lubrication.

 

[dparm]

Are they using any of the newer stuff like antimony?

 

[A_Harman]

No. Antimony didn't show up on the VOA. Polaris tests for it.

 

[dailydriver]

Yes, I would want at least some antimony, boron, or the new Infineum type moly in there.

But, it's shear stability, and TBN look GREAT for a longer OCI.

 

[artificialist]

I was told that what gives JGR oils the advantage over the competition was a higher VII due to mPAO basestocks.

If I saw a VII number it would really please me.

 

[A_Harman]

VI of JGD LS30 is 166.
Pretty much average for a good synthetic these days, but the shear stability is the best I've seen, based on the Temporary Shear Ratio calculation.

 

[JAG]

How do you calculate the tempory shear ratio? I've been calculating it as kv@100C / HTHS or the inverse, depending on how I want to look at it. That would be better if the kinematic viscosity at 100C was instead dynamic viscosity at 150C so the only factor was shear rate. Effect of oil density and temperature would be eliminated.

 

[A_Harman]

You need to have four pieces of information from the oil's spec sheet:

HTHS viscosity
KV100
KV40 or VI
density @ 15C (metric units only, i.e. .85 gm/cm^3. Or specific gravity, which is the same thing in the Metric System.)

a. Use a Viscosity Index Calculator (like Widman) to calculate kinematic viscosity at 150C.
b. multiply density @ 15C by 0.9 to get density @ 150C
c. multiply the KV150 x density @150C. This number is Dynamic Viscosity @ 150C. DV150 is the dynamic viscosity that an oil is expected to have at 150C based on its kinematic viscosity, viscosity index, and density characteristics.
d. divide HTHS / DV150 to get Temporary Shear Ratio. This number represents the fraction of dynamic viscosity at 150C the oil actually maintains when subjected to shear.

 

[JAG]

Thanks!