Re: OIL Controversy!

[ChrisBourk@xxxxxxx]

Here is what I do:

Summer 20/50 Mobil 1
Rest of the year 5/30 Mobil 1

I'd really like to find a better oil but I just don't know of any that are
superior.

Oil is so complex.  The way I see it your engine really needs a straight oil
once warm.  It doesn't care too much what temperature it is outside.  

Some thoughts (of mine) :

Most engine wear occurs during warm up,  I believe this is due to the oil
additives not being effective until they reach a certain temperature, the
failure of oil to stay on bearing surfaces (cylinder walls and valve guides
mostly) after shut down, and the larger than optimal clearences within the
engine - needed to compensate for different coeficients of thermal expansion
during warm up.

What oil?

5/30 allows the engine to get oil presure faster at start up.  On my E-28 it
allows the hydrolic chain tensioner to pump up faster (not rattle as much), it
takes less energy to pump, and puts less strain on the engine.  It cools the
engine better.

20/50 has a higher theoretical viscosity, dampens noises in the engine better
(when warm) and would *presumably* offer greater protection at the margin.

I've been wondering lately if I wouldn't be better off just dumping the 20/50
and running 5/30 all year round.

Does anyone know at what temperatures the different oils reach there specified
weights?  ie. at 200 degrees is 20/50 equal to 30 weight? 40 weight? or 50
weight?

Considering it probably only take 15 or 20 hp to push our cars along at 50 mph
I really don't think either oil is going to make much of a difference on the
street.

FWIW,

Christopher

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