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

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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.

 

OVERKILL

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Why do you feel it needs so much ZDDP? It's DOHC, meaning it doesn't have wickedly high spring pressures like an FT pushrod mill. It's cam-over-bucket, just like most, if not all of the Euro V8's from the same era (Ford used roller followers).

I'd think that any Full-SAPS Euro oil would be more than up to the task.
 
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If you want high ZDDP, you could run any quality CK-4 rated HDEO in 5-40, 10-30, or even 15-40. Those usually have more than 1000 ppm ZDDP, especially if they are not also SN rated. Rotella T4 would come to mind for me.
 
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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.

The Mobil 1 HM was reformulated years ago and is no longer higher in ZDDP - it is around 800 now.

Summit Racing has plenty of high ZDDP oils to choose from and Valvoline VR1 is available in a full synthetic as well. I don't think you need the high ZDDP in the LT5 or any GM engine of the C4 era for that matter. My 94 LT1 runs just fine on Mobil 1 and remember in 1992 all Corvettes came factory Fill with Mobil 1 - LT1 and LT5 so GM is saying with that spec alone that high ZDDP is not needed. So rest well and I would just run the full synthetic of your choice be it Mobil 1, Pennzoil, Amsoil etc.
 
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Arrow

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Why do you feel it needs so much ZDDP? It's DOHC, meaning it doesn't have wickedly high spring pressures like an FT pushrod mill. It's cam-over-bucket, just like most, if not all of the Euro V8's from the same era (Ford used roller followers).

I'd think that any Full-SAPS Euro oil would be more than up to the task.
The flat valve lifters, cams, chains and sprockets of the LT5 were designed with SG oil and its high ZDDP levels in mind. The gurus of the LT5 community always specify a high ZDDP oil for these cars.
 

Arrow

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The Mobil 1 HM was reformulated years ago and is no longer higher in ZDDP - it is around 800 now.

Summit Racing has plenty of high ZDDP oils to choose from and Valvoline VR1 is available in a full synthetic as well. I don't think you need the high ZDDP in the LT5 or any GM engine of the C4 era for that matter. My 94 LT1 runs just fine on Mobil 1 and remember in 1992 all Corvettes came factory Fill with Mobil 1 - LT1 and LT5 so GM is saying with that spec alone that high ZDDP is not needed. So rest well and I would just run the full synthetic of your choice be it Mobil 1, Pennzoil, Amsoil etc.
Yes, I had looked at the Mobil 1's, but as you pointed out, they had dropped the ZDDP levels.

Mobil 1 SG of its time was high in Zinc, at 1300 ppm back then.
 
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I'd prefer to stick to an oil I know meets the needs of the engine, rather then messing with friction modifiers.
The Porsche A40 approval suggestion is more than appropriate here. It’s a far more demanding requirement than what was the API license you’re referencing. More than one example is available at Walmart for a very reasonable price. Other suggestions in this thread are “experimenting” but this one is not.
 
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I think if OP was originally seeking Amsoil, he should check out http://www.hplubricants.com or message the owner @High Performance Lubricants about which exact product to order something equivalent or better. I'm sure they would be happy to fill the order.

Their oils meet or beat A40 as well.

The Walmart available oils mentioned should be fine as well but I heard Amsoil.

OP also mentioned being in Canada as to availability.
 
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