Stuart

        You indeed are correct that a 15w-X or 20w-X Oil is Thicker than a 5w-X Oil

But Only when they are Cold (O�C) ~ It is the Number After the "w-" that relates

to how an Oil will Flow & Protect & Perform @ OperatingTemp (100�C) ~ So when

"UpToTemp" a 0w-40, 5w-40, 10w-40, 15w-40, 20w-40, &SoOn will all Flow, Protect

& Perform Like a Straight40 Oil ~ The Number Before the "w" has LittleToNoEffect

on FuelEconomy because Engines&TheirOil don't stay Cold for VeryLong ~ Also since

most of the Real Damaging Wear that an Eng' incurs happens @ ColdStart & Shortly

After, during WarmUp, it is important to use a MultiGradeOil that has a LowNumber

Before the "w" to insure that the Oil can be MadeToFlow to all the Nooks & Crannys

that need to be Lubed ~ Some "Experts" say that even a 5w-X Oil is to thick to Lube

an Engine Properly @ StartUp ~

        Our H2OBoxers are not Manufactured or even Rebuilt "Loose" ~ They may be

made Loose by ImproperMaintainence ie Being BrokenIn Improperly &or being Lubed

with Oil that is either TooThin OR TooThick ~
	
        Lastly ~ Engines don't get Looser as they HeatUp They get Tighter ~ Materials

Expand in Any&AllDirections they can when heated so an InnerSurface Attempts to

Grow Inward but usually probably can't in areas such as a RoundHole because of the

Forces@Play so an ID will generally StayTheSame ~ But if that ID happens to have,

for example, a CrankShaftBearing Riding in it, that CrankShaft & Its Bearing will be

Expanded due to the heat & the space between the 2 surfaces will get Tighter ~ So

it is, to a certain extent, actually a good thing that Eng'Oils get Thinner when heated ~

        I'll agree with you completely about OilPressurGauges ~ Let them be your Guide

as to the Looseness of your Eng' & the Thickness of its Oil ~ I have an OilPressure & an

OilTemperature in my VDubaru & feel a bit uncomfortable when I am driving a car that

does not provide the info ~

                                                                        ORR ~ DeanB

http://www.bobistheoilguy.com/motor-oil-101/
On 11 May , 2014, at 12:40 PM, Stuart MacMillan wrote:

> The thing about multi weight oils is that 15w- or 20w- oil is physically
> thicker (higher viscosity) than a 5w- anything, and that makes a big
> difference in our loose WBX'ers.  The rating is a lubrication protection
> rating, and 5w- oils are thinner to provide for better gas mileage in modern
> cars.  At high temps an Xw-50 protects like a straight 50w because of
> additives and composition, but is physically much thinner.
> 
> On my '85 purchased in 2012 with 135k on it, I started with 15w-40 dino oil,
> and my hot oil pressure was 28 @ 4000rpm, and 8 at idle, very near the lower
> limit.  I now run Mobil 1 15w-50 with a Mobil 1 high efficiency filter
> (Dennis Haynes recommendation) and my OP is 32 @ 4000, and 10 at idle.
> Better. Next time I might try someone's synthetic 20w-50, which will be
> thicker yet.
> 
> Interestingly, upon cold start @ 60 degrees F with either oil, the OP is 60
> at idle and does not go higher.  Within 5 minutes of driving it drops to 20
> at idle, and 40 at 4000.  30 minutes at 60 mph and it's at the low levels.
> That's the case expanding with heat and opening the main bearing tolerances,
> a design feature every flat VW engine has!
> 
> I also think everyone should have an oil pressure guage. Coupled with oil
> analysis, you'll know what's really going on with your engine.  My first
> analysis on this rig was not very good, and I'm sending another sample soon.
> 
> 
> I live in Seattle where the temps are moderate, but travel in hot eastern
> Washington too, so I run this oil year around.
> 
> Stuart
> 
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> OlRivrRat
> Subject: Re: Royal Purple Motor Oil..
> 
>                John
> 
>        There are a LotOfFolks that say it is OneOfTheBest if not TheBest
> but IMHO it is not better enough to justify the Extra$s ~ I'm curious as to
> why you are wanting to shift from 15W-50 to 20W-50 as they are both 50weight
> oils when WarmedUp & Unless you live in a Climate that is like they get in
> the Southern1/2 of Arizona or NM or Texas & you are being told by an
> OilPressureGauge that your Eng' is Old&Loose there is no need for the Number
> BeforeThe "W" to be any higher than 5 ~