acea a3/b4 and a5/b5 HTHS

[shDK]

Hi all.

Was just comparing acea a5/b5 with a3/b4 with the lubrizol relative oil comparison tool (k think it,s called)

Even thogh the a3/b4 have a higher HTHS at 3.5 compared to the a5/b5,s 2.9. They where identical on the antiwear probertys. Can that really be true? Or is it falls?

Thanks.

Søren

 

[RamFan]

Thicker oil =/= more protection.

 

[Quattro Pete]

Originally Posted By: shDK
Can that really be true?

Yes.

 

[skellyman]

Sure

 

[CATERHAM]

Yes it can be true depending on the oil temperature both oils are being tested at.
But as you raise the oil temperature the lighter A5/B5 oil will reach the boundary lubrication zone before the A3/B4 oil does, all other factors being equal such as DI package and base oil chemistry.

 

[Shannow]

CATERHAM, it's not temperature, it's fundamental design.

Bearing projected areas and loadings, operating speeds etc., and yes temperature as a single parameter determine the viscosity requirements of a system.

Thus the "severe service" nomenclature versus "designed to be capable of using low friction, low viscosity oils" between the two ratings.

 

[supercity]

Originally Posted By: shDK
Hi all. They where identical on the antiwear probertys. Can that really be true? Or is it falls?

Thanks.

Søren



The standard required, lets say the minimum standard required, maybe the same, but that does not necessarily mean the oils are the same.