Idling in snow

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Tony Houghton saying something like:

Hmm.. possible; I've never looked for one. It's a Mk6 2001, and very definitely DI (the only mechanical DI in the Mk6 range, afaik). I was thinking of selling it, but it's worth so little now that I'll just keep it and do a motorhome conversion on it. Only got 60K on the clock, so plenty of life left.

But why would A/C cut off? After all, it can be mixed with hot air to provide conditioned warm/hot air into the cabin as happens in our fully climate-controlled car.

"Pete Zahut" gurgled happily, sounding much like they were saying:

Risk of the condensate drain freezing and blocking.

It's one of the reasons why I don't find running the A/C automatically to assist demisting of much value.

I've pulled the connector off the switch that triggers mine...

Chris

How does that help?

It stops the A/C running when demist is selected.

I've never found it of much use, possibly because I do a fair amount of short runs. Demisting using the A/C clears the screen slightly more quickly, but when you park, then get back in the car, it mists up quicker than before.

Add to that the fact that, as has been pointed out, the A/C doesn't run below 4C, and it's in the winter that you need demist most, so I prefer not to have the A/C coming on automatically.

Chris

I rarely require demist on mornings at or around freezing, because de- icing the windows with tap-hot water warms the inside of the glass as well - so they tend to be clear.

It's when it's warmer and damp that I find the windows mist most rapidly and thoroughly, requiring demisting. Which aircon doesn't just do "slightly more quickly", but a shitload more quickly - and more thoroughly, getting the rear side windows far, far, far more quickly.

Because the heat exchanger can freeze solid.

Mine lives "indoors"!

I will readily concede that my Focus has poor heating and ventilating. The A/C is the same as fitted to the KA, so perhaps that's why it's not that effective at assisting demisting. The biggest problem I have with doing it that way is when you get out of the car, then back in. As soon as the blower starts, the screen fogs worse than it would naturally do.

I find that more inconvenient than waiting a bit longer for demist to be done without A/C.

Chris

there are many priuses in cold united states that have no problems and they get minus 30 C. so quite how cold it has to be before there is serious degradation in performance I don't know, but it doesn't seem likely the uk will have a problem, and in any case the engine just starts and runs when needed, so even very low batteries are not a problem and would warm up quickly once in use. The original Prius had a Turtle symbol show on the dash to say that the batteries were cold and performance would be down, I think that has been dropped from the later types, but might show somewhere on the computer.

"Mrcheerful" gurgled happily, sounding much like they were saying:

The fact that the cars are absolutely mobile doesn't mean the battery performance isn't degraded, of course - they may be relying more heavily on internal combustion power.

quite possible, the owners don't seem to report a problem though from looking at the usa prius forums. For this country it really would not be an issue afaics. Unless of course a new ice age comes in............. If the weather is that cold then a prius will not really be the vehicle of choice for people that must stay mobile, a petrol landrover would be the thing to have.

some makers do not endorse idling for long periods to protect catalytic converters, but in the cold that should not be a problem.

Many CR diesels will no sustain operating temp when left to idle with a thermal loading on them - i.e. the heater, especially in cold conditions, such is their efficiency.

Indeed many have 3 or 4 heater plugs in a little coolant manifold controlled by the ecu to help with warm up, heater operation and maintaining the engine at a temperature.

Tim..

My old 5 cylinder 2.4 diesel Alfa from 2001 was always a cold car in cold weather. However, my 3 litre diesel BMW (E90) is amazingly warm. From a cold start, just idling, it'll produce warm then hot air after just a few minutes. I originally thought it must have some kind of electrical heating in the vents but I suspect it's idle is not very efficient and is just burning lots of fuel. It is rather nice when it's cold outside though..

Doesn't it have a Webasto auxiliary heater as standard? I thought all diesel E90's did?

Chris

However, my 3 litre diesel BMW (E90) is amazingly warm.

it has

I don't think that is available for UK spec cars.

That would explain the cold idle fuel consumption..