[Diy_efi] Re: Zinc and o2 sensors

[David Allen]

  Not really wanting to argue- but... The linked pictures below show a car
having a 3.1V6 with 15W40 Rotella oil, cranked and running at a temperature
of -16?F (-27?C). The company I work for called me to a training class at
the factory in Jackson, MN.  It was on or about January of 2003; during a
cold snap. The engine turned over slower than usual but fired right up no
problems. This car at that time had a junkyard MAF-based multiport EFI setup
that was a replacment for the original 2-bbl carb.
  And to further amaze you - until this point this car hadn't been further
north (north = "cold" in US) than Memphin, TN! It was so mizerably cold that
morning, I stepped out of the motel and cranked the car early. The exhaust
froze and fell to the ground behind the tailpipe, and by time I was ready to
leave, there was a 1/4" (6.4mm) thick pile!
  On the flip-side of this issue- next year I went to Jackson, in my other
car with a 305.  This time I installed Mobil One 0W40 oil before the trip.
It didn't get nearly as cold that year, but it did get down to -6?F (-21?C).
With the  0W40 oil, the engine cranking speed was only slightly slower
at -6?F than it is with 15W40 oil in a moderately cool temperature such as
40?F (4.4?C). That oil really works.
  David

http://home.hiwaay.net/~davida1/temp/FrozenExhaust.jpg
http://home.hiwaay.net/~davida1/temp/FrozenExhaust2.jpg

Ps - US simple-minded warm climate southerners are easily amused by oddities
such as frozen engine exhaust! :-)

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----- Original Message ----- 
From: "Torbj?rn Forsman" <torbjorn.forsman at gengas.nu>
To: <diy_efi at diy-efi.org>
Sent: Sunday, February 05, 2006 1:46 PM
Subject: Re: [Diy_efi] Re: Zinc and o2 sensors


> That depends on the climate. SAE 15W40 will have higher viscosity at low
> temperatures and may cause difficult cold starting below, say, -5 or -10
> ?C. But in a warm climate or in the summer, an SAE 15W40 oil will not
> cause any problems.
>
> /Torbj?rn Forsman