Unleashedbeast

One thing people here need to remember....

Mobil 1 0W-40 is a lighter 40 grade, almost a 30 grade. The differences between it and a heavy 30 grade would be splitting hairs.

Funster_2011V6

I'm glad you mentioned that as its something I noticed after searching BITOG and manufactures sites, and also one of the things that prompted me to open this thread as I don't see it as such a big leap since the cSt specs are so close at temp.

Since you chimed in here, let me ask you this. I like the fact that this oil doesn't seem to adhere to the low zddp requirements of the API and I'm assuming that's because the API has no influence in Europe. However, I'm fairly certain that euro cars have catalytic converters, so what the heck is the API thinking?

Or has the 0w40 been reformulated and no longer contains the 1200 ppm of zinc I'm seeing on BITOG?

everett

I get a kick out of these guys who talk about 5w20 and tighter tolerances. The Aussies get the same cars with the same tolerances yet they get recommended a 5w30. What gives. I am gonna stick with 5w30 in the winter and 10w30 in summer. Well until my big amsoil order comes in then it's 0w30 all the way.

Funster_2011V6

Disregard

JAJ

Yup, but it doesn't matter much.

Under running conditions, engine oil temps can easily range up and down by 10 degrees celcius around the average temperature as loads and speeds vary. What's interesting is that a typical 5w-20 at 90 degrees Celsius is the same viscosity as a 5w-30 at 100 degrees or a 0w-40 at 110 degrees. In other words, the viscosity change of any of the three viscosities will overlap the others as temperatures change.

In performance engine applications, the real deciding factor between different lube products is the HTHS (High Temperature High Shear) viscosity, measured at 150 degrees Celsius. That's the temperature and righ rate of sliding near-contact that occurs in piston rings and crank bearings. SAE J300 HTHS viscosity specs are:

SAE xw-20 - 2.6 Cst minimum at 150 degrees Celsius
SAE xw-30 - 2.9 Cst min
SAE xw-40 - 2.9 (x<=10) or 3.7 Cst min (x>=15)
SAE xw-50 or more - 3.7 Cst min

In the real world:

Redline 5w-20 - 3.3 Cst min
Mobil 1 0w-40 - 3.7 Cst min
Heavy duty 10w-30 (diesel) engine oil - 3.7 Cst min.

From your engine's standpoint, Redline 5w-20's high HTHS and Mobil 1 0w-40's "normal" HTHS make the two products surprisingly similar to each other. Furthermore, their relatively high HTHS levels make them both very different from the rest of the API SM 5w-20's and 5w-30's on the rack at your local store.

Unleashedbeast

Recent VOA sheets I've seen for their 0W-40 have ZDDP in normal API SM range. It has been reformulated to meet the newer certification.

The additive package took a huge hit thanks to API SM.

BruceH

That would be me. I'm one of those guys.

Unleashedbeast

CAFE laws, not tighter tolerances, is why Ford recommends 5W-20.

BruceH

How do you know that? Did Ford issue a memo somewhere?

ShadyNinja

they must use a completely different 4.6 in Australia then right?
because those cars get 30 wt not a 20