I have been using the Castrol 40 W for years in my 91 Vanatgon.  167000
miles later it is still going strong.
cheers
Jaime

> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]On Behalf
> Of Al Brase
> Sent: Saturday, September 03, 2005 1:09 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: heaviest oil to use??
>
>
> Jonce:
> I'm a big believer in straight weight 40w oil (Shell, in my case). Unlike
> multi vis oil which starts out as 10 weight and then has VI
> improver added,
> straight weigh oil is that weight and the polymers won't break down over
> time to becom a thinner oil. (That's how I understand it anyway!)
> Synthetic is a somewhat different ballgame.
> I usually run the 40w oil 9 months a year. Until the thing won't start in
> the winter.. then pour in some MMO to thin it down, drive it to
> the shop and
> change it. I've never seen a problem with this plan in the last 6 years. I
> drive this thing spiritedly to say the least The speedo needle WILL reach
> 100. (but it has 195/75-14 tires, so it is only 90+!
> I guarantee that at 500 miles what i drain out is very much more viscous
> than 20-50!
> Starting routine makes me drive slowly for about 1 mile, so that
> helps warm
> up the oil.
> Al Brase
> 87gl
> 82 diesel
> 80 westy
> 69 double cab
> 56 pickup
>
> On Mon, 29 Aug 2005 08:10:00 -0400, Jonce Fancher
> <streetbugs@WHISPLLC.COM>
> wrote:
>
> >Hi all
> >i need to change the oil in my 85 westi. ive run Marvel oil for while to
> loosen up everything (ie lifters,valves mainly) so now it is time
> to adjust
> the valves and put
> >in fresh oil and filter. the oil i usually use is 20-50 but have heard of
> sae 40. the motor is not new and the oil light did come on after freeway
> flying before i put in
> >Marvel oil. i would like to use a heavier/ thicker oil since i
> will have a
> little marvel oil still in the case during the oil change. can anyone tell
> me if a thicker oil is out
> >there?? maybe used in diesels? i know hyploid oil 80-90 is thicker (Just
> kidding). by the way the van is running on all cylinders has a little
> hesitation when
> >stepping on the gas and is a bit sluggish but i also know it was fully
> loaded with camp gear and a family of 4 so im not supprised. thanks Jonce
> >if there is an archive on this let me know and i will check it out.
> >
> >Jonce Fancher
> >
> >57 Single Cab
> >66 Sunroof Bug
> >66 Variant Squareback
> >71 Sunroof Bus
> >75 911S Sunroof
> >84 Vanagon "Godfried"
> >85 Vanagon Westi
> >2003 10 Passenger Sprinter
> >
> >Fancher's Upholstery Inc. -  www.fanchers.com
> >Not-A-VW Club- http://mywebpages.comcast.net/jaransont3/notavwclub/
>