Date:         Wed, 21 Aug 2002 12:13:23 -0700
Reply-To:     mike <mwmiller@CWNET.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         mike <mwmiller@CWNET.COM>
Subject:      Re: Oil Weight Recommendation
Comments: To: jbrush@aros.net
In-Reply-To:  <200208211709.g7LH9ZK3062919@mail.aros.net>
Content-type: text/plain; charset="US-ASCII"

AFAIK, and so I've been told [by my ex brother in law who worked in the oil
industry for years] multi weights are almost as good at their extremes as
single weight, but not quite.  I.E. 10-30 isn't as good a 10 weight as
straight 10 or as good a 30 as straight 30.

Most of the time it's good enough and the fact it can do both functions
makes it better overall.

However, in applications where the best is needed, at either extreme, the
single weights are used.  Examples are racing and maybe air cooled vans in
hot weather, I don't know about that though.  For water cooled and most air
cooled multi weights are really better overall, usually.

This could all be wrong of course.  Ask David B, he usually has the straight
scoop.

Mike

> From: John Brush <jbrush@AROS.NET>
> Reply-To: jbrush@AROS.NET
> Date: Wed, 21 Aug 2002 11:09:43 -0400
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Oil Weight Recomendation
>
>>> But that doesn't explain why 10-30W is not good for it. Although the hp
>>> output of the mower may exceed that of my van....... :-)
>
>> HP isn't the criterion, its the internal design of the bearing, engine
>> lube pressure,
>
> I was joking :(
>
>> 10-30W could be far too low viscosity under cold conditions.
>
> I seldom mow my lawn when it is snowing <g>
>
>> Think of the origins of the classification system - a large body of
>> knowledge about straight oils and little if
>> any about multi-weight oils.
>
> Are you inferring that no one knows anything about multiweight oil?
>
>> Another tip is to trust that design engineers know a little bit more
>> about what they've designed than they are usually
>> given credit for, especially when it comes to Vanagons!
>
> I am a design engineer, and I wouldn't trust anyone blindly about
> anything....
>
> So I should blindly trust one engineer who makes a great car, and ignore
> the ones who make the oil?
>
>
>
> Still no answers on why anyone should use straight weight over multigrade?
>
> At higher temps, is 20-50W the same viscosity as just 50W?
>
> Thanks,
>
> John
>