Hi.
I have made a similar post in the C6 General Discussion forum with some mixed results.

I have done some research on engine oils, and I am considering using German Castrol 0W30 oil in my soon to be C6 (built as of May 7).

The German Castrol (only comes in 0W30) appears to be far superior to the "American" Castrol, as well as far superior to Mobil 1 5W30.

My concern is that the C6 Manual clearly states "use 5W30".

Furthermore, the German Castrol does not have the GM 4718 rating - but I have read they have submitted the product to GM for testing

The last thing I want to do is wreck my LS3 by using the incorrect oil.

Am I looking for trouble in going with the Castrol Syntec 0W30?

M........

 

Really?

I guess that is why cars from Acura (RDX), Aston Martin, Bentley, Mercedes-Benz AMG, Mercedes (SLR), Porsche, Nissan's flagship GT-R and the Viper SRT-10 all come with German Castrol from the factory (not to mention the C6 and Z06)?

Oh wait, they don't. They are all factory filled with Mobil 1.

 

The German Castrol is an excellent oil and I have used it in my '06. Mobil 1 has apparently changed it's formula over the last few years and from what I've read it is not the oil it used to be.

It seems some members here worry about their warranty and the oil they use but have no problem modding their car with everything from headers to cams. It has been mentioned here many times nobody can recall a single warranty issue over the oil in the crankcase.

IMHO the bottom line is use the Castrol and give your car a better oil than Mobil 1.

OK, flame suit is all buttoned up!

 

OK - I'll jump in with one question - WHY? I see many posts - Amsoil vs. Mobil 1, German Castrol vs. Mobil 1, etc. IF you change the oil on a reasonable basis (annually if you drive little, via oil monitor, every few thousand miles, or whatever you like) do you really think that one brand of "premium" oil vs. another is going to make a difference in longevity of the engine? I don't. Even running the car hard on a track - how many mechanical "failures" are due to a perceived engine oil failure? Just trying to be realistic here. Pursuing that perfect oil won't hurt anything - but I think it's just extra expense that adds nothing significant to your engine longevity. Anyone have a C6 that "consumes" oil? I sure haven't heard or read of any and a few are getting up in mileage.

 

Mike,
The German Castrol 0w30 is a very good fluid. If you are willing to try an American alternative, the previous generation AMSOIL Series 2000 0w30 compares well to the GC 0w30:
Used Oil Analysis Comparison: German Castrol 0w30 vs AMSOIL Series 2000 0w30

Here is a very recent oil analysis on my personal 06 CTS-V (LS2) using the same oil:
Cadillac CTS-V Used Oil Analysis – Mobil 1 5w30 vs AMSOIL 0w30

The Series 2000 0w30 was replaced late last year with the new AMSOIL Signature Series Synthetic 0w30. This oil is recommended by AMSOIL for your LS3, labeled by AMSOIL to meet GM 4718M, and warrantied by AMSOIL: AMSOIL Corporate Warranty

I haven't tried it yet, but intend to pick some up and drop it in my CTS-V with its next oil change.

 

I ran GC 0W-30 because it's almost a 40 weight according to Patman. I ran it for 1 oil change based on Patman's recommendations, but have since switched to Penzoil Platinum 5W-30 also based on Patman's recommendation (plus it's Corvette approved). Also, the GC is sometimes very tough to find.

 

All valid points, if you are going to have a stock or near stock weekend warrior car that you probably won't put more than 10k on it before you sell it, it really doesn't matter. But for me I plan to have a 650rwhp SC car that is making a lot more power than GM designed the engine to handle. Therefore it only makes sense to go with the best oil that suits your car. For me the GC is the best all around for my needs, tests have shown it has the best cold crank flow of any 0w getting oil quickly to vital parts (anyone who understands engines knows the cold start up is hardest on it) and as stated earlier the GC performs almost like a 40 at 100 C. at 12.1 Obviously adding a SC is going to add more heat and I want the added protection under hard pulls.

And yes there are many reports that M1 is using base 3 in the blending of their oil, maybe thats why they are able to sell it for 20 bucks a gallon at Walmart.

 

Do you think they put in M1 because they know it's the best, or maybe, just maybe M1 pays them to put it in?

 

I'm interested why you say that the German Castrol "appears to be far superior to the "American" Castrol"...what evidence have you seen ?

 

You can do a lot of research on BITOG.com (Bob is the oil guy) All american Castrol is made with base 3 oil and not all 4 (its a blend), Why? I don't know why I can only assume $$. The german stuff is made totally different from the American base and performs better in every way.

 

I don't know what the availability is there in Ontario, Canada but here in the USA, German Castrol has pretty much disappeared. The AutoZone chain was carrying it, and for a while after discontinuing it, some stocks languished on the shelves of some stores, but that was years ago now and it is gone.

There is a special forum on BobIsTheOilGuy forums for German Castrol, if you are inclined to do research there.

 

Interesting...

 

Autozone now carries it again, I think they were bring in new stock and wanted to sell out all the old first.

 

FWIW, I prefer to use oil with a viscosity recommended by the engineers who designed the car. If GM says 5w-30 is best, that's what I'll use. If GM says to use oil meeting their 4718 standard, then that's what I'll use.

I have no problem with Castrol, Mobil 1, Quaker State, or any other oil, as long as it meets the specs called for by the designer of my engine.

 

Just FYI:

Castrol makes SLX Professionla 4718M - which is mainly sold in Canada.

GC 0W-30 is probably not the best thing for the LS7, at least (which I have)

I have a friend also with a C6Z06. We changed our oils together for the last two oil changes and found the following:

I gave my car its second oil service at ~3K miles. Put in M1 5w-30.

My buddy changed his oil at ~14K miles. He put in M1 0W-40. (previously used M1 5w-30)

Well about 3K miles later, we did another change and found the following:

I dropped my oil, both drain plugs had little debris and few hairs, virtually no mud.

He dropped his oil and each drain plug had a large mound of black/grey mud with plenty of hairs. He completely freaked out. When he wiped it off, it was like a grey goo on the shop towel. He had at least 10X the amount of metallic debris than I did.

So, needless to say he switched back to M1 5W-30.

Not to say that any other product is better - I just was amazed when I saw that result and made me wonder if I really wanted to mess with OEM recommendation. (I've been strongly considering switching)

Type of driving: both about the same - daily driver with some spirited canyon runs.

Oil pressures and temps: his pressures were higher than mine and temps were lower - significantly lower - about 10 to 20 degrees lower from just standard daily driving. Looks like that is not a good indicator of quality of oil APPLICATION as well.

Moral of the story: unless you are driving hard to the point of cooking the M1 5W-30 - you may want to reconsider changing it out for something else.

By the way, he had tiny little black specs floating around in his used oil. I did not. I'm betting he added about 30K miles of simulated wear on his engine by using that oil on a daily driver.

Just my 2 cents

 

IMHO GC 0W-30 is the BEST oil out there. I would NEVER use M1 5W-30 in any of my cars. Now, that is my personal opinion based on reading others research and I will not get into an oil argument. Everyone has their own preference and I don't think any oil on the market is bad or will damage your engine.

Yes, GM uses Mobil 1 5W-30 in every vette that leaves the factory and if you believe that is because it is the best and not because of marketing then I have no interest in trying to change your mind.

 

if it was such junk then wht would they give you a 100k mile warranty?

 

I am running my first fill of GC 0w30 in my '08 Vette (~1,000 miles). I have the older "green stuff" though. I have about 40 qts to use up between my Vette and my Firehawk. I also use LC20 in the oil and FP60 in the fuel, just like I do in my Firehawk. Comparing two different oils in two different cars is pointless...lol Hell, based on UOA's, wear metals between two of the same model engines using the same oil could look completely different. There is not one "best" oil, what's optimum for one engine may not be optimum for another.

 

 

Because chevy knows that the vast majority of Corvette owners will never see 100,000 miles within 5 years (if ever.) Then, after 5 years and the engine is out of warranty, chevy would love
for their engine to be worn out. It's the perfect crime if you think about it. Chevy isn't stupid. They might be bankrupt, but they're not stupid!