Of course it varies by car.
I was talking about my lotus elise - which I have set such that I have LCD
blocks showing my petrol amount and underneath the coolant temperature as "XXX
C" - ie a figure. If you can join the rest and ignore Lee's vendetta-fest for
a moment I can explain that usually the figure says 87 whilst driving and
mid-nineties in a traffic queue. The handy thing about it showing deg C is
that I'm easily alerted when it goes above 100 (ie it looks much different).
In fact with the Elise it can go up to 108 (I believe) after which it starts
flashing. I cannot remember when you're meant to pull over and turn off the
engine (fortunately it never happens). But the point was - '100' is my 'alert
facture'. A good number by all counts.
You are correct that the antifreeze/corrosion inhibitor 'widens' the properties
of water but my point was - in the car it works much nicer using C with water
as the 100 point (to me) would mean something. In deg F it would always be
triple figures (when running). Obvously Lee's ('Ken') point was - like his
crop of other 'post TSO holiday' entries - to make me out to be "all wrong and
making it up" but I am sure that most here would understand my real logic of
preferring deg C when the substance being used was (mainly) water.
By the way - my mini (subject of other conversations here, usually distorted by
two contributors) uses a pressurized system and thus raises the boiling point
considerably higher still. Always quite scary after a good drive as the engine
bay is roasting hot and you can almost hear pops and bubbles in the system -
but the good old mini was meant to run that way!! The temperature gauge in
that car shows water temp in F and oil pressure in lb/sq in. For both sides of
the gauge there is a needle so the best way to read it will always be "bad if
it's too far down" for oil pressure and "bad if it's too far up" for
temperature - ie the unit used becomes less of a focal point as it does in the
Lotus - which actually quotes the figure. I also have a Honda Civic which
simply has a dial and will be taking delivery of a Triumph Stag this weekend -
which also has a unitless dial.
Cheers (cars are always a good subject!!!)
Steve
P.S. If anyone has doubts over any of the posts that a certain person has laid
his boots into then feel free to continue emailing me (privately or not) where
- as always - I'll explain how the pedantry can be seen to work (albeit
temporarily). ;-)
Date: Mon, 13 Apr 2009 18:50:08 -0700
From: [email protected]
Subject: [USMA:44674] Re: Stephen's fantasy imperial Britain
To: [email protected]
Actually, the antifreeze will elevate the boiling point and depress the
freezing point. At least in US cars, the coolant MUSTN'T be water, as the
pressure cap alone is not sufficient to keep water from boiling. You need the
coolant to at least approximate the recommended 50% antifreeze mixture.
Overheat indication is around 135 °C, with 130 °C in the normal range. With a
104 kPa / 15 PSI pressure cap, water will boil about 124 °C and is not a
satisfactory coolant.
--- On Mon, 4/13/09, Ken Cooper <[email protected]> wrote:
From: Ken Cooper <[email protected]>
Subject: [USMA:44669] Re: Stephen's fantasy imperial Britain
To: "U.S. Metric Association" <[email protected]>
Date: Monday, April 13, 2009, 8:25 PM
OK - Let's dissect Stephen's post.
The LCD display showed my engine temp in Celsius - I have it that way as the
coolant is water - thus? I think you can see my thinking here!! ;-)
A beautiful example of Stephen's misdirection! I find it very hard to believe
that his car has a coolant system that works with pure water at atmospheric
pressure. The coolant mixture is highly unlikely to boil at 100 degrees C as he
implies. The anti-freeze will lower the boiling temperature and the fact that
the system is pressurised will act in the opposite direction.
In addition, I've never owned a car that displays the coolant temperature in
any other way than a uncalibrated gauge. Can Stephen confirm which car he has
that displays coolant temp via a digital display & how it indicates that the
coolant temp is too high?
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