On Thu, 12 Feb 2009 15:39:05 -0500, wrote:

On Thu, 12 Feb 2009 09:14:23 -0500, wrote:

On Tue, 10 Feb 2009 20:29:46 -0600, Steve Barker
wrote:

..

the lighter oils are purely a gas saving thing. Has nothing to do with
the lubricating requirements. It saves gas when figured on a million
engines at a time.

Sorry, but I can't really buy that. The lighter oils may be
in part for better mileage but they are also for better protection.

I wonder how many people realize that the first number is only
used to describe the oil when it is cold and the second number
describes the oil when it is at operating temperatures.

Yes, so? what would be wrong with a 0W50 in place of a 5W20?

All else being equal and assuming that 50W when hot would meet
the needs of the engine and that 0 would not be too light when cold
(hardly seems likely to me) than it should be fine.

Cold lubrication would be a non-issue because Ow flows better cold
than 5W, and hot protection would be better because 50 doesn't thin
out as much hot as 20 - The ONLY reason to use a 5W20 would be better
fuel mileage due to thinner oil requiring less power to pump.


And you can't buy 'old' oil anyway. Nearly EVERY oil on the shelf has
certification for every new engine.

Certainly not mine. I drive a diesel and it is picky about
the oil it uses.

Picky how? Is it a Turbo Deisel? Then it needs the top line turbo
deisel oil. Otherwise MOST deisels will run any good C rated oil like
Rotella T 15W40.

I use 5W40 CF Rotella myself, but that is for my 2002 TDI I
don't believe it meets the requirements of the current 2009 VW US spec
diesel.


And there is a fair bit of oil available out there that does not meet
the latest and highest spec.


steve