Mobil 1 0w40 and Castrol Edge Sport 0w40 an info..

[Massimo_A]

Mobil 1 NEW LIFE:
Viscosity, cSt (ASTM D445)
@ 40º C 75
@ 100º C 13.5
Viscosity Index 185
HTHS Viscosity, mPa•s @ 150ºC, (ASTM D4683) 3.8
Flash Point, ºC (ASTM D92) 230
Density @15.6 ºC, g/ml (ASTM D4052) 0.85


Castrol Edge Sport 0w40
Viscosity, cSt (ASTM D445)
@ 40º C 75.7
@ 100º C 12.8
Viscosity Index 171
HTHS Viscosity, mPa•s @ 150ºC, (ASTM D4683) 3.6
Flash Point, ºC (ASTM D92) 244
Density @15.6 ºC, g/ml (ASTM D4052) 0.838


What do you thing about this 2 oil?
I'm very undecided, both are ok for the specification with my engine (Alfa Romeo Giulietta with JTDm 2.0 Diesel, 170cv).
What do you thing about? What of this 2 oils is more shear stable? An advice please

My engine requires ACEA B1/B3 specification and so both these oils are OK, but Castrol meets also C3 specification (this could be an advangage or disadvantage in an engine without particulate filter?).

 

[Radman]

I am sure they are both good, but I would put my money on the Castrol products.

 

[BMWTurboDzl]

Unfortunately castrol does not sell this oil in the US so I would say to use which ever oil meets the spec for you car and if both do then use whichever is the cheapest.

 

[cmf]

I wish we had Alfa Romeo in the US.

The Castrol Edge has a better flash point but I'm not sure you'd have any issues with the 230 flash point of the M1.

As far as more shear stable, that would be the Mobil 1. It's HTHS is 3.8 compared to Castrol's 3.6 (higher is better). HTHS stands for high temperature high shear.

About the ASTM D4683 test:

"Significance and Use

Viscosity values at the shear rate and temperature of this test method have been indicated to be related to the viscosity providing hydrodynamic lubrication in automotive and heavy duty engines in severe service.

The viscosities of engine oils under such high temperatures and shear rates are also related to their effects on fuel efficiency and the importance of high shear rate, high temperature viscosity has been addressed in a number of publications and presentations.

1. Scope

1.1 This test method covers the laboratory determination of the viscosity of engine oils at 150 °C and 1.0·106 s−1 using a viscometer having a slightly tapered rotor and stator called the Tapered Bearing Simulator (TBS) Viscometer. "

 

[A_Harman]

It looks like the Castrol would be a little more shear stable than the Mobil.

 

[Gene K]

M1
Higher HT/HS
Yet already a lower viscosity at 40C.
Higher VI

Castrol might or might not be more shear stable. Depends on exactly how the higher VI was achieved on the M1 (Might just have better quality base stock).

 

[m37charlie]

I'd prefer the Mobil 1. It has a higher HTHS and higher viscosity at 100C. Although not listed, I will bet its' TBN is higher also.

Charlie

 

[dparm]

The Mobil 1 looks better. Higher VI, higher HTHS in the same weight.