Using 5W-30 In Engine Specified for 10W-30

[GMorg]

GoldenRod

Yes, PP is a Group V base. Like RayH suggested, Group V is a "trash can" designation. It means "everything else" or "not Groups I-IV". I like to think of it as the "happy family" designation or may the "supreme diversity" group.

 

[Terry]

Heres a very accurate way to know if the API licensed oil you are interested in for that 3.8 could be used regardless of vis spread. Using the the Corvette GM 4817M spec.

If a lube can clear that hurdle then it is truly stable enough regardless of vis to make the grade.

One of a few times that bench testing can help you the consumer in a meaningful way.

I don't have time to list all the oils that meet that spec ( not many can) in 5w30,0w30,etc. but one I am aware of is Pennzoil Platinum 5w30.

Most syn oils that meet this spec are indeed 10w30 so if the brands chemistry passed with another vis it is incredibly well formulated, by being low wearing as well as oxidatively and deposit resistant.

Terry

 

[GoldenRod]

Terry,

So then are you saying that Pennz Platinum 5w30 would work in the GM 3.8L V6?

 

[Terry]

Yes, I would based on meeting GM4817M. And those darn GM guys ( most of who probably lost their jobs today) are pretty hard on candidate corvette approved oils.

For warranty if you want to dot the i and cross the T then use a 10w30.

You internet quick fellas see what other syn brands meet GM4817M in any grade besides 10w30 and post them here. I bet the list is small.

Terry

 

[04SpecV]

Do you mean GM4718M
Mobil 1(regular) 5W30
Castrol Syntec 5W30
Amsoil ASL 5W30

They have it listed, but does that mean they were tested for it?

[ March 29, 2006, 02:34 AM: Message edited by: 04SpecV ]

 

[The Critic]

Terry,

The correct name for the Corvette oil specification is the GM 4718M. There are only three GM 4718M approved oils on the market on my 5/2005 list:

Chevron Supreme Synthetic, 5w-30/10w-30
Mobil 1, 0w-30/5w-30/10w-30
Texaco Havoline Synthetic, 5w-30/10w-30.

All are GF-4.

My list does have Pennzoil Platinum but it only shows Pennzoil Platinum as being approved for GM 6094M.

All other oils may claim to meet GM 4718M but are not approved for GM 4718M by GM. Whether or not you feel comfortable using them, you decide for yourself...

The list may've been updated since 5/2005 so I'll double check, but its unlikely.

 

[Terry]

Spec, my late night "slysdexia" kicked in and the bifocals don't help, I am so sorry to post the GM spec incorrectly! bruce381 did you slip some of that vino in my tea last night??

Yes GM4718M is the license. For a lube maker to post and or claim that a product has been tested and passed the spec it must meet ALL requirements and MAY NOT claim conformance to just one aspect of the testing only.

Pennzoil Platinum 5w30 and 10w30 meets the requirement because I am looking at the GM acceptance letter dated 2/2005.

If a company claims to "meet" the standard it may be true but they cannot legally say that if not submitted to GM. If there is a question about a particular product please ask the marketer for the GM letter to verify.

Mike I don't think your list is up to date.

With all this said there is one aspect of the test I want to focus on and there are differences that few of us will ever see for proprietary reasons.

ASTM 6891 or sequence IVA Cam wear average: the limit for 4718 is 90 um max , some oils show very low wear in this and others barely squeek by. The key is UOA will show slightly elevated wear in cam, ring and cylinder wear elementals( that signature varies in each engine). Using the product that shows lower wear rates is key to get the best bang for the buck regardless of brand name.

 

[The Critic]

quote:

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Pennzoil Platinum 5w30 and 10w30 meets the requirement because I am looking at the GM acceptance letter dated 2/2005.

---

My list is dated May 2005. If the GM acceptance letter is dated February 2005, then it should definitely be included on the 4718M list for May 2005. And yes, GM does know about Pennzoil Platinum, as they have it on their 6094M approval list for May 2005.

I'll post my list a little later, or does anyone have an updated copy of the list?

 

[GoldenRod]

I realize that most of you guys are sick to death of me harping on this issue; but are 5W-30 and 10W-30 oils interchangeable with each other in ALL engines? Meaning, if 10W-30 was to disappear off the face of the earth, and there was still plenty of 5W-30, would it be harmfull to an engine that is used to running with 10W-30?

Would there be ANY occasion where you would not want to use 5W-30 in place of 10W-30 and visa versa?

 

[G-MAN]

quote:

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Originally posted by GoldenRod:
If 10W-30 was to disappear off the face of the earth, and there was still plenty of 5W-30, would it be harmfull to an engine that is used to running with 10W-30?

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I'll go out on a limb and say that any engine that is spec'd to run on 10w30 will do perfectly fine on modern 5w30 oils.

 

[GoldenRod]

^^^^ That's what I was waiting to hear.

 

[Nickdfresh]

I agree. But there's nothing wrong with running 10W-30 when it's warm, and 5W-30 during the cooler months. That's what I would do if I had your much newer 3800V6. Mine has over 169,000 miles on it, and I am sure that it's had both 5W-30 and 10W-30, but mostly the latter I'm guessing... The 1990 vintage 3800 "preferred" 5W-30, so I am very curious as to why GM went to 10W-30 as the preferred oil sometime in the mid-90's...

It's uses very little oil, and comes out only a little darker then it went in after 3000-4000K OCIs (so far)...

You won't hurt that engine, even if you put in Wesson cooking oil or Crisco in it. (but I wouldn't recommend that.

)