0W40?

[Hib Halverson]

Thanks for the replies, folks.

For those who use M1, the latest 0W40 is "Mobil One Supercar". Among others, it's the factory fill on C8s w. LT2s. M1 "Supercar" is the 10W40 ESP that was rebranded.

[Paul Workman]

Every time this question comes up, some are quick to say they have tried it in their motors w/o any issues. But, lubrication issues seldom pop up until considerable run time has occurred under typical wear scenarios or under stressful scenarios.

I dunno 'bout Uz, but I can't afford to experiment with my engine - too rich for my not-so-deep pockets. Therefore, I would prefer to see some comprehensive, scientific testing and comparisons between historic results with a former recommendation lubricants and the new product (good as it may be!).

Our LT5s are flat tappet motors and rev limits are ~ 7100 rpm to 7500 rpm (in some modifications). And, the ZDDP of the oils recommended at the time they were being built (by Mercury Marine), the zinc/phosphorous levels were in the ~1200/1300 ppm - to accommodate the demands of those (LT5) engines.

However, air pollution mandates resulted in reducing (in part) the ZDDP levels. And, offsetting the reduction of reducing the ZDDP, flat tappets gave way to roller tappets and rocker arms, etc.; both roller tappets and rockers are still in use today. My point is: aren't we comparing apples to oranges here? That isn't to say that this or that GM oil recommendation will spell trouble for our first gen LT5s. But, it remains to be seen if the new oil recommendation can bridge the gap between the specific application (roller tappets/lower rpm vs. flat tappets/high rpm) requirements.

Your mileage may vary. But, as for me - I'll stay with the "Kool-aid" until something else proves to be better...hopefully in an application other than MY LT5! Just sayin'

[Dynomite]

Originally Posted by Paul Workman

Every time this question comes up, some are quick to say they have tried it in their motors w/o any issues. But, lubrication issues seldom pop up until considerable run time has occurred under typical wear scenarios or under stressful scenarios.

I dunno 'bout Uz, but I can't afford to experiment with my engine - too rich for my not-so-deep pockets. Therefore, I would prefer to see some comprehensive, scientific testing and comparisons between historic results with a former recommendation lubricants and the new product (good as it may be!).

Our LT5s are flat tappet motors and rev limits are ~ 7100 rpm to 7500 rpm (in some modifications). And, the ZDDP of the oils recommended at the time they were being built (by Mercury Marine), the zinc/phosphorous levels were in the ~1200/1300 ppm - to accommodate the demands of those (LT5) engines.

However, air pollution mandates resulted in reducing (in part) the ZDDP levels. And, offsetting the reduction of reducing the ZDDP, flat tappets gave way to roller tappets and rocker arms, etc.; both roller tappets and rockers are still in use today. My point is: aren't we comparing apples to oranges here? That isn't to say that this or that GM oil recommendation will spell trouble for our first gen LT5s. But, it remains to be seen if the new oil recommendation can bridge the gap between the specific application (roller tappets/lower rpm vs. flat tappets/high rpm) requirements.

Your mileage may vary. But, as for me - I'll stay with the "Kool-aid" until something else proves to be better...hopefully in an application other than MY LT5! Just sayin'

Excellent Summary Paul

[spork2367]

Originally Posted by Paul Workman

Every time this question comes up, some are quick to say they have tried it in their motors w/o any issues. But, lubrication issues seldom pop up until considerable run time has occurred under typical wear scenarios or under stressful scenarios.

I dunno 'bout Uz, but I can't afford to experiment with my engine - too rich for my not-so-deep pockets. Therefore, I would prefer to see some comprehensive, scientific testing and comparisons between historic results with a former recommendation lubricants and the new product (good as it may be!).

Our LT5s are flat tappet motors and rev limits are ~ 7100 rpm to 7500 rpm (in some modifications). And, the ZDDP of the oils recommended at the time they were being built (by Mercury Marine), the zinc/phosphorous levels were in the ~1200/1300 ppm - to accommodate the demands of those (LT5) engines.

However, air pollution mandates resulted in reducing (in part) the ZDDP levels. And, offsetting the reduction of reducing the ZDDP, flat tappets gave way to roller tappets and rocker arms, etc.; both roller tappets and rockers are still in use today. My point is: aren't we comparing apples to oranges here? That isn't to say that this or that GM oil recommendation will spell trouble for our first gen LT5s. But, it remains to be seen if the new oil recommendation can bridge the gap between the specific application (roller tappets/lower rpm vs. flat tappets/high rpm) requirements.

Your mileage may vary. But, as for me - I'll stay with the "Kool-aid" until something else proves to be better...hopefully in an application other than MY LT5! Just sayin'

The ONLY reason 0w oil was created was to reduce emissions and increase fuel economy, primarily during a vehicles warm up period. Anyone who says anything else is drinking the corporate kool-aid from the auto manufacturers. I spent years at a company that built air cooled aircraft engines that were used in environments with starting temps well below zero and places with starting temps well above 3 digits. We've done our research and operate in a market devoid of emissions regulations (for the time being). Zero weight oils were created in Japan for emissions and fuel economy. You know, the country where it was cheaper to buy a new car than to continue to run a car with 55k miles due to emissions and other restrictive requirements like the "shaken" law.

There is no measurable benefit to 0w oils on start up unless you are comparing them to straight 50 weight or gear oil. Sorry. The car manufacturers and the government are trying to dupe you.

Run what the manufacturer recommended originally or slightly heavier depending on driving conditions and style. That recommendation came from before the environmentalists became so woke and figured out how much money was in it. While additive packages have improved, there is no magic to oil manufacturing from the 90's until now. It is almost exclusively driven by CAFE and emissions laws.

My 2011 Subaru Forester came with 0w 20 oil from the factory and the timing chain clattered like none other at startup until I switched to a heavier oil.

[Matt B]

Originally Posted by spork2367

The ONLY reason 0w oil was created was to reduce emissions and increase fuel economy, primarily during a vehicles warm up period. Anyone who says anything else is drinking the corporate kool-aid from the auto manufacturers. I spent years at a company that built air cooled aircraft engines that were used in environments with starting temps well below zero and places with starting temps well above 3 digits. We've done our research and operate in a market devoid of emissions regulations (for the time being). Zero weight oils were created in Japan for emissions and fuel economy. You know, the country where it was cheaper to buy a new car than to continue to run a car with 55k miles due to emissions and other restrictive requirements like the "shaken" law.

There is no measurable benefit to 0w oils on start up unless you are comparing them to straight 50 weight or gear oil. Sorry. The car manufacturers and the government are trying to dupe you.

Run what the manufacturer recommended originally or slightly heavier depending on driving conditions and style. That recommendation came from before the environmentalists became so woke and figured out how much money was in it. While additive packages have improved, there is no magic to oil manufacturing from the 90's until now. It is almost exclusively driven by CAFE and emissions laws.

My 2011 Subaru Forester came with 0w 20 oil from the factory and the timing chain clattered like none other at startup until I switched to a heavier oil.

Very interesting post. Thanks!