What is "Plan B" if I can't get Amsoil Z-Rod for My 1990 Corvette ZR-1.

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The supertech 5w40 would need a VOA for better info concerning the meets/exceeds on the bottle label. Anyone using it?

Napa around here has the Valvoline VR1 full synthetic 10w30 ... usually with an inch of dust on the bottles. Still a viable good choice.
https://bobistheoilguy.com/forums/threads/valvoline-vr-1-10w-30-reformulation-voa.329804/

Don't forget about OP's location and product availability. Should post a picture of the oil shelf at the local autopart/deptstores. 10w40 synth motorcycle oil might just trump some of the fancy stuff. Castrol/Mobil1 full synthetic 10w40's 4t MC oils are truly great oils for those not hung up on SP/GF6
 

Arrow

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The supertech 5w40 would need a VOA for better info concerning the meets/exceeds on the bottle label. Anyone using it?

Napa around here has the Valvoline VR1 full synthetic 10w30 ... usually with an inch of dust on the bottles. Still a viable good choice.
https://bobistheoilguy.com/forums/threads/valvoline-vr-1-10w-30-reformulation-voa.329804/

Don't forget about OP's location and product availability. Should post a picture of the oil shelf at the local autopart/deptstores. 10w40 synth motorcycle oil might just trump some of the fancy stuff. Castrol/Mobil1 full synthetic 10w40's 4t MC oils are truly great oils for those not hung up on SP/GF6
Could you please explain the 4T MC part?
 

OVERKILL

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Btw, does anyone know the Zinc rating of the Mobil 1 FS 0W40?
I wouldn't obsess about Zinc/Phos levels, but the Full-SAPS Euro oils, like this one, are higher:
Screen Shot 2022-07-01 at 1.06.16 PM.png


It's a better oil, in every respect, than anything that was spec'd or available for that engine when it was new.
 
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My 1990 Corvette ZR-1 with the Lotus designed LT5 will be going in for some servicing the first of next week, and I won't be able to get my usual Amsoil Z-Rod 10W-30 by then. The LT5 wants its high ZDDP levels, so standard oils in the 800-900 range won't work.

I was looking for the High Mileage Mobil 1 at the local Wal-Mart, and all they had was 0-20 and 5-30.

Being in Canada, some of the smaller brands that can be bought in the US aren't easily available up here.

Any plan B recommendations? Oils that would do lesser harm?

Liqui Moly MoS2 Anti-Friction 10W-40 has been recommended as a viable option, but I'm not that familiar with it. Seems the ZDDP levels are good in it.


Have you considered that the car may easily be able to wait until fall for its next oil change? That Z-Rod oil is a very stout product, most people do not put nearly enough miles on in a season to "use it up".
 
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Odd, because:
View attachment 106065

Footnote (4), no maximum for API SP or SN Non-ILSAC grades. ILSAC grades are indicated on the top row: 0W-20, 0W-30, 5W-20, 5W-30 and 10W-30.

This is referenced on the Phosphorous (9) line, with the limit of 0.06 - 0.08 (4), (10)

Hmmmmm.

But.. what about Zinc? (It appears there is "no maximum" for Phosphorus, like your article states)
 

OVERKILL

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Hmmmmm.

But.. what about Zinc? (It appears there is "no maximum" for Phosphorus, like your article states)
There's no maximum for Zinc, it's not defined. As @RDY4WAR has gone into in the past, Zinc is just there to neutralize the Phosphorous. Phosphorous is what started being capped, starting with API SM.
 
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There's no maximum for Zinc, it's not defined. As @RDY4WAR has gone into in the past, Zinc is just there to neutralize the Phosphorous. Phosphorous is what started being capped, starting with API SM.

Ahh. I get it now.. and with API SN and SP it is un-capped.

Thank you, OVERKILL! 😀
 
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There's no maximum for Zinc, it's not defined. As @RDY4WAR has gone into in the past, Zinc is just there to neutralize the Phosphorous. Phosphorous is what started being capped, starting with API SM.

Now, for extra credit.. maybe.... do you think OP is over-thinking the ZDDP part of oil for his LT5 Corvette engine? Or not necessarily. (Sounds like he could have done well with QS Defy, if ZDDP was a thing.)

I've asked myself a ZDDP question in the past, as well, now I'm leaning towards that maybe oil has come past needing ZDDP to protect an engine that may have needed it when it was made.
 

OVERKILL

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Ahh. I get it now.. and with API SN and SP it is un-capped.

Thank you, OVERKILL! 😀
No, lol, it's only not capped for the non-ILSAC grades.

Starting with API SM, Phosphorous was capped at 800ppm for all the ILSAC grades. So your 0w-20, 5w-20, 0w-30, 5w-30, 10w-30.
 

OVERKILL

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Now, for extra credit.. maybe.... do you think OP is over-thinking the ZDDP part of oil for his LT5 Corvette engine? Or not necessarily. (Sounds like he could have done well with QS Defy, if ZDDP was a thing.)

I've asked myself a ZDDP question in the past, as well, now I'm leaning towards that maybe oil has come past needing ZDDP to protect an engine that may have needed it when it was made.
Well, that was my point with my first post in this thread. It's an engine that's cam-over-bucket, very much the same as most of the Euro V8's that spec'd a Full-SAPS oil like M1 0w-40 (hence my recommendation). Proof of performance is validated through extensive testing as not only part of A3/B4, but also A40, 229.5, 502 00/505 00 and historically, LL-01 before 0w-40's were no longer being approved for that one.

Phosphorous is an important anti-wear component, which is why we see it used so universally. ZDDP also has an LSPI mitigation mechanism to it, so decreasing the levels exasperates LSPI, which is why we saw calcium being reduced (replaced with magnesium) to try and counteract that. That's also why the Euro marques that spec'd Full-SAPS oils weren't having LSPI issues with TGDI.

With the reduction in phosphorous, other compounds were used, some of them organics that don't show up in VOA/UOA's, to make up for the loss of its AW properties.

It seems, the "sweet spot" for phosphorous for AW in a sliding contact/follower arrangement is around 1000-1100ppm, if we consider the Euro lubes that didn't have any restrictions on phosphorous as being our barometer for that. Of course that's part of an overall fully formulated package with other complimentary components in the blend, and has been rigorously tested.
 
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Well, that was my point with my first post in this thread. It's an engine that's cam-over-bucket, very much the same as most of the Euro V8's that spec'd a Full-SAPS oil like M1 0w-40 (hence my recommendation). Proof of performance is validated through extensive testing as not only part of A3/B4, but also A40, 229.5, 502 00/505 00 and historically, LL-01 before 0w-40's were no longer being approved for that one.

Phosphorous is an important anti-wear component, which is why we see it used so universally. ZDDP also has an LSPI mitigation mechanism to it, so decreasing the levels exasperates LSPI, which is why we saw calcium being reduced (replaced with magnesium) to try and counteract that. That's also why the Euro marques that spec'd Full-SAPS oils weren't having LSPI issues with TGDI.

With the reduction in phosphorous, other compounds were used, some of them organics that don't show up in VOA/UOA's, to make up for the loss of its AW properties.

It seems, the "sweet spot" for phosphorous for AW in a sliding contact/follower arrangement is around 1000-1100ppm, if we consider the Euro lubes that didn't have any restrictions on phosphorous as being our barometer for that. Of course that's part of an overall fully formulated package with other complimentary components in the blend, and has been rigorously tested.

And that would also be why a 0W-40 would make sense because it isnt subject to an 800ppm cutoff!

800ppm is lower than 1000-1100ppm 🙂
 
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Supertech 5w40 VOA would show the z/p levels, and is all the OP was looking for..... If the VOA showed a 300/400 p/z level, would you believe the label at all? or is it more believable when 1000/1100ppm?

Whats not to like about a 10w40 MC oil?

Motorcycleoil.jpg
 
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