GC 0w30 or M1 0w40 in an LS2?

[Grave]

I just purchased a used 2005 GTO about a month ago. Car currently has 6,3xx miles on the odo. The prior owner used to use M1 0w40. The GTO isn't a daily driver... I might drive it once or twice a week, maybe 1-2k miles a year if that. At any rate, my oil changing schedule would call for changing the oil at 5,000 miles/6 months, which ever comes first. Considering my driving habits for this car, the oil will be changed every 6 months. So now it's time for an oil change, and I was wondering which oil would be more suitable for an LS2 in a desert climate... ... GC 0w30 or M1 0w40 .... ... or does it even matter, taking into consideration how infrequently I drive the GTO? I know LS1's like thicker oils, however I wasn't 100% sure if the rules would still apply to a Gen IV LS2 or not, or if an LS2 likes a different oil better. BTW, the reason I chose these two oils is because both are highly recommended in LSx engines, and both are readily available for local purchase where I live.

 

[427Z06]

Either will work, but GC is preferred.

 

[bighead]

*wipes the drool from the keyboard* First off.... Second, nice ride. I'd love to have one of those....*more drool* lol. Third, me personally I'd chose GC as I've used it before with good results. This being in a not-so-high powered vehicle (04 Grand Am 3400 V6). The GC would serve you and that sweet ride well. Enjoy!!

 

[Alan]

M1 5w30 once a year,you'll never have an oil problem.

 

[NewC6]

I am running GC in my 05 and it seems to like it. This is based on the recommendations of people on this board. I do NOT have a UOA on this engine with GC. I run the oil about 7K then change. Once this is gone, I am back to running Amsoil. Not saying M1 is bad, I am saying I think there are even better oils for the LS2. A couple of UOA's on an LS2 and many on LS1's seems to indicate these motors like an oil thicker than M1. But be sure and do some research on this board. I think you might come to the same conclusions. Good luck

 

[427Z06]

quote:

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Originally posted by NewC6: A couple of UOA's on an LS2 and many on LS1's seems to indicate these motors like an oil thicker than M1.

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M1 is no longer considered thin at 11.3 cSt. GC is 12.1 cSt, thus it's not significantly thicker anymore. Further, there's actually very little evidence that LSx engines prefer thicker oil under all circumstances. GC worked well in the LSx engines and people concluded it was because it was thicker, when actually it's just a better formulated oil.

 

[Win]

I just use plain Havoline synthetic 10/30 in my LS1 powered GTO, beginning at about 450 miles, and changed every 3K since. It has never consumed any discernible quantity of oil, and has never had any piston slap.

 

[Patman]

I still have not seen an M1 5w30 UOA in an LS1, LS2 or LS6 engine that was really super impressive.

 

[dkryan]

Grave: I know nothing of LS1s, 2s, or 6s, but I do know that if you are actually driving just 1-2k miles per year (did I read that correctly?), I'd use a high quality filter, M-1 or GC, and change it once per year.

 

[manicrodder]

I changed oil in my 06 Goat at 1000 miles. I installed PP 5w30 and it seems to be doing well. It is as quiet as the Mobil 1 factory fill. I will have it analysed when it reaches 2000 miles on the PP. For what its worth, The PP meets the GM 4718 spec but the GC does not state the same.

 

[Grave]

quote:

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Originally posted by dkryan: Grave: I know nothing of LS1s, 2s, or 6s, but I do know that if you are actually driving just 1-2k miles per year (did I read that correctly?), I'd use a high quality filter, M-1 or GC, and change it once per year.

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That is correct... 1000-2000 miles per year. I really only drive it on Fridays to work, and on the weekends when I'm cruising or going to the track/dyno. That's about it! I will use the K&N filter. I used it on my 2002 Z28 Camaro when I had it, and it's a great filter. I used to use RP 5w30 in the Z28, but I want to try something different in the GTO.

 

[427Z06]

quote:

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Originally posted by Patman: I still have not seen an M1 5w30 UOA in an LS1, LS2 or LS6 engine that was really super impressive.

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And your point is?

 

[buster]

quote:

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I still have not seen an M1 5w30 UOA in an LS1, LS2 or LS6 engine that was really super impressive

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Patman, have you ever performed a tear down? What about Redline? Have you seen a good UOA with RL? Many people who change to RL see improved bearing wear in raced engines, yet on BITOG, you would think bearing wear is elevated. You can't just assume that what you see from a $20 report is telling you the whole story. I think that is where many people go wrong. M1R 0w-30 is 10cSt, yet was tested by Joe Gibb's racing and came out 2nd, behind their own oil. These guys are probably pushing 750hp out of engines. Again, it's just more complicated than what you see here. IMO.