Optimal oil for a C6 Corvette?

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I've just purchased a used C6 with 110K miles this past month and I'm looking to take the best care of it that I can. Daily driver, I'm not going ham on it 24/7, currently lightly modified (headers-back and intake) so I know I'm overthinking all of this but that's just how I do things...

Part of what is messing me up is GM and Mobil1 putting out the new 0w-40 spec for the late C7 models and current C8s, especially since in Europe many C6s have been running 0w-40 for a while. But people have been running the usual 5w-30 for decades so I'm guessing it's not really that important?

Then my dad was going on about Amsoil and how awesome it is so I've gone down a rabbit hole of PAOs and esters and group iii/iv/v and whatnot but it seems they don't even advertise that they use the good stuff anymore... I've seen their Z-Rod stuff with high ZDDP being suggested for modified LSs but I haven't read much about that kinda oil. I don't know if it'd be best to get some heavily protective oil that needs changed more often (more intended for racing applications?), something fancy like Amsoil Signature or an extended performance/high mileage oil that can be left in there for a ton of miles or just get something that's cheap, meets spec, and I'll chang it every 5k miles. I know 99% of it is marketing but I can hardly understand half of it lol.

Mostly been thinking of going with PUP 5w-30 (5 bucks a quart on amazon, seems cheap enough), a NAPA Gold filter, and calling it a day. Maybe get some oil analysis kits for the current unknown fill and a few subsequent changes, not sure if Amsoil or Blackstone or elsewhere would be the best option there. I don't have much in terms of service records so I'll probably try and change the transmission oil soon too. Hell probably all of the fluids in the car need flushed... anyone got some pointers?
 

ZeeOSix

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I'd say the 5W-30 would be fine for normal street driving with some short durations of getting on it now and then. But if you hammer it hard quite often and/or just want some engine protection headroom, then run the 0W-40 that Chevy specs for the C7 and C8.
 

VeganJoy

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I'd say the 5W-30 would be fine for normal street driving with some short durations of getting on it now and then. But if you hammer it hard quite often and/or just want some engine protection headroom, then run the 0W-40 that Chevy specs for the C7 and C8.

Pretty much what I've concluded as far as viscosity, and I have yet to see oil temps over 220F so I bet the 30 weight is perfect so far. Just not sure which 5w-30 since there's so **** many to choose. I'm sure 99% of them are good enough but still lol
 

VeganJoy

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Considering it is the MOFT that keeps parts separated and this is related to the HT/HS there’s little downside to one with a somewhat higher HT/HS.
i vaguely understand the terminology but i'm not sure if you mean a higher weight or lower

PUP 5w30 is all you need.
how about the filter? i've read that a lot of the common GM filter replacements from a decade ago have been replaced with inferior products i.e. the corresponding wix and purolator filters
 
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No need to overthink it. Any full synthetic 5w-30 will be fine for your LS2/LS3 and change it when you feel you need to. I usually change mine around 25% left on the OLM. Some have used 40w for hard track usage. I use the Mobil One M-113a filter.
Two things to check asap...
1- Harmonic balancer wobble. All LS2/LS3 will have this issue. It's a matter of when and not if this happens. Had to replace mine at 50k miles. Approx $1200 to have it done. It's a pain in the ass job even with access to a lift and knowledge of how to do it. It's a 6.5hr job by the book.
2- LS2/LS3 with headers are known to cause the starter to fail more quickly due to the extra heat and larger diameter tubes. The connection where the positive battery cable attaches to the solenoid becomes brittle and fails.
Other than that, I would definitely change every fluid unless you know it has been recently done. There is nothing complicated for any fluid change other than getting the car high enough to get under it to do it. Transmission is best to use a fluid exchange machine if you have an auto. There are YouTube videos available for anything you can think of doing. Check around some local shops and see if any of them are running a service special if its out of your skill set. OEM spark plugs are 100k interval, so those should be checked as well.
Corvettes are notorious for being temperamental with batteries. Put a fresh one in and use a tender if it sits for over a week just for peace of mind. OnStar is a known source of parasitic draw, pull the fuse and forget about it. C6 uses 2G cell technology for OnStar and will not work at all in the very near future.
 
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If not running it hard or tracking it.....5W30 is more than adequate. Use a full synthetic from your favorite brand.

The PF48E gets some hate, But I've never seen one cause damage. I run a UPF48R on my L92 (Converted to LS3) engine.
 
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Mobil 1 HM 5w30 or M1 0w40

On a track Redline Oil or something with esters. Get in with the Corvette guys. They will know the most if not too much
 
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i vaguely understand the terminology but i'm not sure if you mean a higher weight or lower


how about the filter? i've read that a lot of the common GM filter replacements from a decade ago have been replaced with inferior products i.e. the corresponding wix and purolator filters
MOFT means "maximum oil film thickness". Simply means that a thicker oil will have a thicker protective oil film.

Oil filter, I'd swing by the GM dealer and get an oem one.
 

ZeeOSix

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i vaguely understand the terminology but i'm not sure if you mean a higher weight or lower.
To add to what aquariuscsm said above ... the higher the HTHS (High Temp High Shear) viscosity (not all oil makers show that spec), the thicker the MOFT will be which will give more oil film between moving parts, which means better wear protection. Valvoline Advanced 5W-30 full synthetic is also a very good oil.
 
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PUP 5W30, in my experience, has always been that one oil that burns of quicker than anything else. Not sure why, but no matter what engine I used it in - it always disappeared quickly from the crankcase. Not leaking out, but burning off.

I'd just use one oil, from short trip grocery run to long track day. That oil is Mobil 1 0W-40. Very stout oil, meets many stringent requirements and certifications, including my favorite - Porsche A40.


Here is Porsche A40 testing procedure:
This test will last 203 hours. The engine, and the oil, will go through:
- 4 times the simulation of 35 hours of summer driving,
- 4 times the simulation of 13.5 hours of winter driving,
- 40 cold starts,
- 5 times the simulation of 1-hour sessions on the “Nürburgring” racetrack,
A full lap of the Nordschleife, bypassing the modern GP track, is 20.832 km (12.944 mi) long. A stock Chevrolet Corvette C5 has a lap record at Nurburgring @8:40, stock Honda S2000 has a [email protected]:39, and stock Honda NSX is @8:38. Considering these numbers, this Porsche A40 simulation is equal to 80-90 miles of flatout track use. Or 100-120 miles if you drive Porsche 911 GT2 R with its lap record @6:38.
- 3.5 hours of “running-in” program
Measurements on the engine and on the oil will be done at regular intervals, and the following parameter
will be taken into account to grant the approval or not:
- torque curve (internal friction),
- oxidation of the oil,
- Piston cleanliness and ring sticking,
- Valve train wear protection. Cam & tappet wear must be less than 10 μm.
- Engine cleanliness and sludge: after 203 hours, no deposits must be visible.

- Bearing wear protection: visual rating according to Porsche in-house method.
One more thing for comparison. Just a rough idea of how the numbers stack up. Take everything with a grain of salt.
Most daily driven cars have an average speed (over the course of an OCI) of about ~35mph. That would make the 203hr test an equivalent to 7,105 miles of driving.
Assuming the average speeds are higher, let's say 50mph, and the 203hrs are now equivalent to 10,150 miles of driving.
 
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MOFT means "maximum oil film thickness". Simply means that a thicker oil will have a thicker protective oil film.
Actually it's "minimum oil film thickness" but your description is correct, for the most part. (y)
Oil film thickness is affected by many factors, viscosity / viscosity range being one of them.
 

VeganJoy

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No need to overthink it. Any full synthetic 5w-30 will be fine for your LS2/LS3 and change it when you feel you need to. I usually change mine around 25% left on the OLM. Some have used 40w for hard track usage. I use the Mobil One M-113a filter.
Two things to check asap...
1- Harmonic balancer wobble. All LS2/LS3 will have this issue. It's a matter of when and not if this happens. Had to replace mine at 50k miles. Approx $1200 to have it done. It's a pain in the ass job even with access to a lift and knowledge of how to do it. It's a 6.5hr job by the book.
2- LS2/LS3 with headers are known to cause the starter to fail more quickly due to the extra heat and larger diameter tubes. The connection where the positive battery cable attaches to the solenoid becomes brittle and fails.
Other than that, I would definitely change every fluid unless you know it has been recently done. There is nothing complicated for any fluid change other than getting the car high enough to get under it to do it. Transmission is best to use a fluid exchange machine if you have an auto. There are YouTube videos available for anything you can think of doing. Check around some local shops and see if any of them are running a service special if its out of your skill set. OEM spark plugs are 100k interval, so those should be checked as well.
Corvettes are notorious for being temperamental with batteries. Put a fresh one in and use a tender if it sits for over a week just for peace of mind. OnStar is a known source of parasitic draw, pull the fuse and forget about it. C6 uses 2G cell technology for OnStar and will not work at all in the very near future.
I checked and the M113a wasn’t recommended for the LS2. But I’m guessing it still fits fine? And do we know the OEM for M1 filters?

Already checked the harmonic balancer before purchase. I think I’ve heard about the starter issues, no idea on the specifics of the exhaust other than the long tubes and FM catback but you think I could have a shop coat/wrap the headers now?

Any suggestion for new spark plugs and would it be prudent to replace the wires while I’m in there? Will be sure to use some anti seize on reinstall as I’ve heard that’s a good idea, not sure what metal base to use though

Battery is like 2 years old, holds 14.4V steady still. Tender in place if I let it sit but it is my daily. 1LT so no Onstar, probably for the best lol

PUP 5W30, in my experience, has always been that one oil that burns of quicker than anything else. Not sure why, but no matter what engine I used it in - it always disappeared quickly from the crankcase. Not leaking out, but burning off.

I'd just use one oil, from short trip grocery run to long track day. That oil is Mobil 1 0W-40. Very stout oil, meets many stringent requirements and certifications, including my favorite - Porsche A40.


Here is Porsche A40 testing procedure:
This test will last 203 hours. The engine, and the oil, will go through:
- 4 times the simulation of 35 hours of summer driving,
- 4 times the simulation of 13.5 hours of winter driving,
- 40 cold starts,
- 5 times the simulation of 1-hour sessions on the “Nürburgring” racetrack,
A full lap of the Nordschleife, bypassing the modern GP track, is 20.832 km (12.944 mi) long. A stock Chevrolet Corvette C5 has a lap record at Nurburgring @8:40, stock Honda S2000 has a [email protected]:39, and stock Honda NSX is @8:38. Considering these numbers, this Porsche A40 simulation is equal to 80-90 miles of flatout track use. Or 100-120 miles if you drive Porsche 911 GT2 R with its lap record @6:38.
- 3.5 hours of “running-in” program
Measurements on the engine and on the oil will be done at regular intervals, and the following parameter
will be taken into account to grant the approval or not:
- torque curve (internal friction),
- oxidation of the oil,
- Piston cleanliness and ring sticking,
- Valve train wear protection. Cam & tappet wear must be less than 10 μm.
- Engine cleanliness and sludge: after 203 hours, no deposits must be visible.

- Bearing wear protection: visual rating according to Porsche in-house method.
One more thing for comparison. Just a rough idea of how the numbers stack up. Take everything with a grain of salt.
Most daily driven cars have an average speed (over the course of an OCI) of about ~35mph. That would make the 203hr test an equivalent to 7,105 miles of driving.
Assuming the average speeds are higher, let's say 50mph, and the 203hrs are now equivalent to 10,150 miles of driving.
Sheesh that sounds like a really good standard, is there a way to view what oils meet certain standards or would I just have to look at each one individually? And what M1 0w40 is that, it seems they have quite a few variants

Post some pictures of this beast you’ve purchased. We love car pics!
As you wish! :)

F553600F-8053-46CC-874F-5866A071B320.jpeg


I must say, it looks dramatically better in pics and from 20 feet away lmao. I really need to find a shop to do some work on the paint and panels, but it’s kinda hard finding anyone decent near me…
 
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I checked and the M113a wasn’t recommended for the LS2. But I’m guessing it still fits fine? And do we know the OEM for M1 filters?

Already checked the harmonic balancer before purchase. I think I’ve heard about the starter issues, no idea on the specifics of the exhaust other than the long tubes and FM catback but you think I could have a shop coat/wrap the headers now?

Any suggestion for new spark plugs and would it be prudent to replace the wires while I’m in there? Will be sure to use some anti seize on reinstall as I’ve heard that’s a good idea, not sure what metal base to use though

Battery is like 2 years old, holds 14.4V steady still. Tender in place if I let it sit but it is my daily. 1LT so no Onstar, probably for the best lol
Looks like Chevy did update their oil filter spec in 2007 to a PF48. If you have a 2005 or 2006 model then it takes the PF44 or 46. The M1 for those is M1-107. The filters are the same size physically, but have a different thread mounting pitch, so they are not interchangeable apparently.
Stick with OEM spark plugs and wires. I've seen enough issues with different plugs and wires that I wouldn't mess with what works just fine.
Not sure if a shop can wrap the headers now that they are installed. Not worth it to have them removed just to wrap them. For the money you would throw at it for that, I would probably just replace the starter for peace of mind and I believe there is a bolt on heat shield available to help protect the starter.
 

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Sheesh that sounds like a really good standard, is there a way to view what oils meet certain standards or would I just have to look at each one individually? And what M1 0w40 is that, it seems they have quite a few variants
The "regular" Mobil 1 0W-40 FS. Meets Porsche A40.

0a6fc5c4-1084-4e82-acfb-a57d7e7176ba.3382b02b2346af218e84b90673d97fb7.jpeg

There is an ESP version with green label, and that one is mostly for European diesels. Meets Porsche C40 (diesel emissions friendly)
mob-123875_go.jpg
Click here for list of Porsche A40 approved oils. Sometimes you can look at the back of the bottle and see which standards/certifications an oil claims to meet. Just remember: "Meet & Exceed" is not the same as "Approved". If in doubt - ask BITOG, or check oil manufacturers website. Most of the time - oils rated for "European" vehicles end up meeting much more stringent specs/certs than basic API SP 5W30.

For myself - Mobil 1 0W40 or Castrol Edge 0W40 is what I use in everything: from my liquid-cooled 4.3hp 49cc scooter, to a 375hp 4.6L Huyndai Genesis, and 7 other vehicles in between (V6, V6-hybrid, I6, I4, few single cylinder engines). Truly a universal oil.
 
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