VI of M1 0w40 vs GC 0w30

[MarkStock]

So I'm a few months away from an oil change in my MB with the 5.5 V8 and am eyeing the various oil deals.

The car is under warranty so I'm looking at 229.5 approved oils.

M1 0w40 has a HTHS of 3.8 & a VI of 185
GC 0w30 has a HTHS of 3.5 or 3.6 & a VI of 175

M1 0w40 shears quite quickly so I presume it's HTHS then will match GC 0w30 as it shouldn't go below 3.5.

But it's VI will presumably still be 185 which is higher than GC.

So out of the two, the Mobil 1, pardon the pun, would have the EDGE?

 

[CATERHAM]

Yes I think M1 0W-40 is a better alround choice although heavier than necessary at operating temp's. The latest SN version of M1 doesn't shear much at all not that it really matters.
BTW the VI of GC is only 167 not 175 the last timei checked. Because of that M1 will be lighter than GC on start-up at all temp's as high as 75F which is the main reason I prefer it.

There are other oils that I do prefer for your application if you can get them such as Lubro Moly 0/5W-30 (180 VI) and Total Quartz 9000 0W-30 (178 VI).

 

[MarkStock]

Thanks!

Can you advise why you'd prefer Lubro Moly or Total Quartz?

Is it because they have the higher VI and run a little thinner at operating temp? Or something else?

 

[CATERHAM]

Exactly, they're lighter across the board.
The lightest oil that meets the Merc 229.5 spec' is what I'd prefer for the way cars are driven here in NA. Fact is all A3 oils are heavier than necessary.
Are there any A5/B5 oils that Merc' approves?
BMW has an alternative LL-01 FE A5/B5 oil for some models. Just wondering if MB has a similar option?

 

[HTSS_TR]

It's hard to get either Lubro Moly and Total Quartz and the price is much higher than M1 0W40 while it's on sale at Pep Boys with coupon 5-qt plus M1 filter for $30. You can thin out M1 0W40 a little with couple quarts M1 AFE 0W20.

 

[HTSS_TR]

Originally Posted By: CATERHAM
Exactly, they're lighter across the board.
The lightest oil that meets the Merc 229.5 spec' is what I'd prefer for the way cars are driven here in NA. Fact is all A3 oils are heavier than necessary.
Are there any A5/B5 oils that Merc' approves?
BMW has an alternative LL-01 FE A5/B5 oil for some models. Just wondering if MB has a similar option?

No. Only A3/B3, A3/B4 for gasoline engines.

 

[CATERHAM]

Exactly, they're lighter across the board.
The lightest oil that meets the Merc 229.5 spec' is what I'd prefer for the way cars are driven here in NA. Fact is all A3 oils are heavier than necessary.
Are there any A5/B5 oils that Merc' approves?
BMW has an alternative LL-01 FE A5/B5 oil for some models. Just wondering if MB has a similar option?

 

[MarkStock]

Originally Posted By: HTSS_TR
It's hard to get either Lubro Moly and Total Quartz and the price is much higher than M1 0W40 while it's on sale at Pep Boys with coupon 5-qt plus M1 filter for $30. You can thin out M1 0W40 a little with couple quarts M1 AFE 0W20.


That's just what I was thinking. But maybe outside of warranty!

With a 9 quart sump and HTHS of 3.8 & 2.6, would 2 quarts of 0w20 take me down to an overall HTHS of 3.5?

 

[CATERHAM]

I'd prefer using the Mobil made Toyota 0W-20 for it's much higher 216 VI. The result would be a heavy (3.5cP) 0W-30 with a 190 VI.

 

[JimPghPA]

I would trust GC to be better for the seals of the engine.