The reason you want a low viscosity multigrade oil is to provide adequate
lubrication/oil flow when cold after intital startup. There is nothing to be
gained by using anything heavier than 10-40 in a good engine that does not
suffer from excessive oil consumption. As a matter of fact fuel economy will
suffer slightly by running too heavy an oil. I live in a warm climate
(SanDiego) and I use 15W-40 in both my MB's.( 190E 146K miles, SL320 105K
We recently purchased a new Hyundai SantaFE with the 3.3 Liter engine and it
calls for 5W-20 oil due to the tight aluminum block clearances.
Hope this helps
I have a 92 230E, 100 kmiles. The viscosity chart in the
car´s manual indicates that I should use a 10w-40 oil viscosity for
temperature conditions where I live.
However every lube shop I go, they recommend using 20w-50 viscosity
of the age / mileage of the car. They say that due to engine wear, a
with more than 60 kmiles should use a thicker oil.
It makes sense. It is just that this car does not show any sign of
yet, at least the ones that I am aware of, blue smoke exhaust and
increased oil consumption.
In that case, and according to what I know (though not much and just
the thicker cold viscosity (two times thicker) would make the cold oil
to flow during winter cold starts, increasing the wear. Also the
viscosity would cause the engine to generate more heat (and hence be
What do you think?