[Vwdiesel] Oil Light/Buzzer

[Drew MacPherson]

OK - (everybody in unison,) ONE MORE TIME!

Let's look at the 5W50 specification, shall we?

5 = viscosity at low temperature (I can't remember if this is 0C for sure)
50 = viscosity at high (operating) temperature - 100C

When it's 0C and I start my car, my 5W50 oil flows the same as 5W30 oil
would, because they have the same low viscocity rating.

When it's -30C out, and I start my car, my 5W50 oil will flow enough to
allow me to start my car.

When it's -30C out and I'm blasting down the highway at 145Km/h and my
5W50 oil's operating temperature is 100C, it flows like a 50W oil would at
100C.  It does not flow like a 50W oil would (or wouldn't) at -30.

If it's so damnned cold that my fridge is running to keep the food from
freezing (like it's been doing lately) and my 5W50 oil doesn't get up to
100C, so what?  When my 5W50''s temperature is say 60C, it does NOT flow
like a 50W oil would at 60C, it will be somewhere in between a 5 and a 50,
and it's probably going to be pretty linear, otherwise there's a lot of
chemists who will be out of work...

In the Northern Hemisphere it is (on average) a lot colder in January than
July - that's why the bulk of us run MULTI-WEIGHT oils, so we can start
our cars when it's COLD and so they still have oil pressure when the
engine is HOT.

Drew

On Fri, 14 Feb 2003, TexasTDI wrote:


> It's a lot colder in January, than July.  That's why you run a thinner oil
> in winter.
>
> Chris Thornton
> 1991 VW Jetta GL 2 Door 1.6D - 234k miles
> 2000 VW Golf GLS 1.9TDI 130hp/229ftlbs - 76k miles
> Amsoil Synthetic Lubricants Dealer #1098500
> http://www.amsoil.com
> http://texastdi.com/6/ubb.x
>
> ----- Original Message -----
> From: "Drew MacPherson" <drew at scirocco.cs.uoguelph.ca>
> To: "TexasTDI" <TexasVWdriver at hotmail.com>
> Cc: <vwdiesel at vwfans.com>
> Sent: Friday, February 14, 2003 3:00 PM
> Subject: Re: [Vwdiesel] Oil Light/Buzzer
> >
> > Obviously you missed the underlying point of my response.  If 20W50 is
> > suitable for OPERATING TEMPS in July, then there's no reason why 5W50
> > isn't suitable for OPERATING TEMPS in January.
>