With today's modern oils there is no reason to have to go to the straight 40 for any temperature. I don't even know straight weights are available with the latest specifications. 20w-50 or 15w-50 will work just as well. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Dave Mcneely
Sent: Saturday, June 04, 2011 9:13 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Spooked!

---- David Beierl <dbeierl@ATTGLOBAL.NET> wrote:
> At 12:38 AM 6/4/2011, Don Hanson wrote:
> >   You can get better oil pressure with heavier oil.  20-50 will get 
> >you through the summer or till you decide to fix the motor or something else.
>
> 15W40, 15W50, 20W40, 20W50 are all specified for temps up to
> 90+.  For temps over 100F the spec is straight SAE 40.  Page 85 in
> the owner's manual for '89.  Incidentally 20W50 is specified down to 
> 10F and SAE 40 down to 70F.
>
> These are standard specs for new engines, not counsels of despair.  
> These engines need heavy oil.

So, in summer in the southern plains, how does one run the multigrade for temps below 100, and the single grade above 100?  The daily temperature range is generally from around 70 to above 90, but on many days (and almost all in a hot summer) the afternoons will be above 100, but mornings still low 70s.

mcneely
>
> Yours,
> DAvid

--
David McNeely