[200q20v] Re: Evans Coolant NPG+

Brandon Hull Hull at cardinalpartners.com
Fri Nov 30 10:01:14 EST 2001

Sorry to come to this thread so late.  I have used Evans in the 3B for
25K miles and I'm happy with it.  I installed it for the reasons Larry
gives.  I use the old formulation, don't know much about NPG+ other than
I've heard it has lower viscosity so works in more applications.  I know
George Baxter discovered it won't work in an AAN engine (the old
formulation) so worries about viscosity with complex cooling plumbing
are real.  But I've had it in my 3B for four years, 25K miles, 40 or so
track days with no problems.  Two minor concerns:  Because the system is
vented to atmosphere, you catch whiffs of coolant smell from time to
time.  I don't notice it now, but it was annoying at first.  You could
run a breather line to some remote location I guess.  Secondly, I live
in fear that if a hose ever does break (less likely w/zero pressure) I
might be able to do an ad hoc repair, but I can't just top up with water
and limp home.  So I carry an extra (v. expensive) bottle in my track
box.  BTW, I never drove the car w/o Evans, so I can't comment on the
relatively higher engine temps, but the car runs cooler by the gauge
than the old 20v NA engine did.  <apologies for quoting the whole thread
here, but it looks like a comprehesive summary of the issues so I'll
leave it intact>

e//S2 3B

-----Original Message-----
From: Larry C Leung [mailto:l.leung at juno.com]
Sent: Thursday, November 29, 2001 3:01 AM
To: brett at cloud9.net
Cc: quattro at audifans.com; 200q20v at audifans.com
Subject: [200q20v] Re: Evans Coolant NPG+

One potential risk (though I'm looking into this myself, as most of my
cooling system is new) is that the temps that NPG ran at (don't know
about the NPG+) are on average higher than EG. THe advantages are more
even head temps (no hot spots to cause detonation) and higher engine
efficiency (due to the Carnot cycle improving with every degree diff btw
intake and exhaust temps). The big advantage ('specially on knock
sensored cars and turbos) is that with reduced detonation, high temp
operation (such as track or fast road driving will have consistant
(same as a cool engine just at op temp) rather than reduced power as
temps rise. That and the lifetime coolant. The higher overall temp MAY
cause the plastic bits a problem though, since temps, not pressure seems
to be the cause of brittleness of things like radiator end tanks and
after-run pumps, heater control valves, heater core endtanks, etc. I'm
considering this, but I'm just not sure.....


On Thu, 29 Nov 2001 00:34:51 -0500 Brett Dikeman <brett at cloud9.net>
>The Big Baby is overdue for a coolant change, and with winter
>approaching, figured now was the time to do it.  I also noticed one
>day that the gurgling noise coming from the engine has returned.
>Well, I'm wandering around the net using Google, checking into Evans
>yet again, but everything points to the stuff being just too thick.
>S-cars can't use the stuff at all, supposedly the pre-C4 cars have
>big enough passageways in the radiator.  Still, it's not
>confidence-inspiring that Evans recommends new radiators+pumps with
>the NPG.  Ah, no.
>Well, lo and behold, Evans has come out with a new version, NPG+.
> From the website(evanscooling.com):
>"A blend of non-aqueous ingredients, NPG+ retains all of the benefits
>of Evans original NPG coolant, while improving upon its thermal
>conductivity by about 32 percent and reducing its viscosity by about
>65 percent. It is perfectly suited for the demands of any hard
>working engine, and there are no plumbing or pump changes needed to
>use this coolant."
>Any thoughts?  I remember a few listers spoke vehemently against
>using NPG, and I -think- it was because of the viscosity problem.
>Well, if they've fixed that, is it worth a go?
>Oh...and I nearly fainted at the price.  Quantities up to 3 gallons,
>$25/gal.  That's some pricey coolant.  It will last the lifetime of
>the car, and one of the toted benefits is a zero-pressure system that
>supposedly makes heater cores etc last longer; if it prevents a
>heater core meltdown, it could easily pay for itself.
>Thoughts? Opinions?  Experiences(with the NPG+ that is)?
>"They that give up essential liberty to obtain temporary
>safety deserve neither liberty nor safety." - Ben Franklin
>http://www.users.cloud9.net/~brett/bdikeman.asc	(PGP Public
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