Why do we all use 50/50 antifreeze/water mix?  Because that's what auto 
manufacturers, including VW say use.  That mixture will protect the 
engine to -37 F.  That's good for almost all the lower 48 U.S. states. 
If it gets colder where you live, use 60:40.  David McNeely

On Wed, Dec 2, 2009 at 9:43 PM, Richard Koerner wrote:

> From the curve, looks like a 60% antifreeze and 40% water mixture is 
> significantly better than a 50/50 mix....wonder why we all do 50/50?  
> Corrosion protection should also be better with more antifreeze...just 
> thinking.
>
> Rich
> San Diego  (doesn't freeze here, that's for sure)
>
> --- On Wed, 12/2/09, pdooley  wrote:
>
> From: pdooley Subject: Re: weak coolant - winter's approaching!
> To: vanagon@GERRY.VANAGON.COM
> Date: Wednesday, December 2, 2009, 7:17 PM
>
> I guess you didn't read the article.
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On 
> Behalf Of
> Michael Snow
> Sent: Wednesday, December 02, 2009 9:44 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: weak coolant - winter's approaching!
>
> On Wed, Dec 2, 2009 at 6:38 PM, Mark  wrote:
>> So here's a question - maybe an easy one... So I'm in the middle of a
>> flush-n-fill with ye olde bus.  I've probably got something like 70%
>> distilled water and 30% coolant in there at the moment (given that 
>> it's
> hard
>> to flush ALL the coolant out).  I can't drain and refill with a 50/50 
>> mix
>> until the weekend.  But I live in Michigan and it's getting COLD!
>  Supposed
>> to get down to 20 degrees F on Friday morning.  Am I doomed?  Will 
>> the
>> water/coolant in the van freeze and cause damage? Or will it just get
> slushy
>> and I'll be o.k. until Saturday?  I tested the coolant and the floaty
> balls
>> tell me I'm good until 20 degrees F.
>>
>> I found this info and chart from the Alaska Science Forum to be kind 
>> of
>> neat.  Apparently, higher coolant mixes don't necessarily mean better
>> protection:
>>
>> http://www.gi.alaska.edu/ScienceForum/ASF6/680.html
>>
>> thanks for you thoughts!
>>
>> --
>> Mark
>> 1990 Westy (2.1 - manual)
>>
>
> Coolant is cheap.  Engines are expensive.  Drain some of your mix and
> add pure coolant until you are satisfied with the protection level.
>
> -- 
> Michael Snow
> 1987 Syncro TiiCo
> 1982 Westfalia 1.9TD
> http://slowmachine82.blogspot.com/