Idling in snow

Think ice cream van...

Anything reasonably modern will run on idle for hours with no problem.

Chris

To add,

Just pop out of the car now and again and make sure the end of the exhaust pipe is clear (if snowing heavily at the time) - just to make sure there is no "occupant damage" :-)

See other replies .. but I've found with my Landrover that at idle it cools down quite a lot! Keep meaning to remove the viscous fan, but cba .. ;)

The fan will have little effect if the thermostat has closed.

It's not a diesel, is it? They tend to produce less waste heat than petrol engines.

I was stuck on the M80 for 8 hours in an Audi A2. Although I did have a sleeping bag I didn't bother to use it as we kept moving forward every hour or so. I ended up switching off until the car felt cold which was after about half an hour then ran it for ten minutes. During that 8 hours the tank only went down by an eight.

Re: the Land Rover post - The Audi has an electric fan which never came on.

I reckon leaving it running continually is not that bad for a modern car but why if you are wrapped up reasonably well you only need to run the engine for about a third of the time?

BTW Does anyone know what happens with one of those "Engine stops when car not moving - restarts when you press the accelerator" cars? Can you keep the engine going when stopped?

Slatts

All the energy is turned into heat when idling as no mechanical energy is produced. Both cars will do 0mpg.

This is where the Prius comes into its own.

Once you've powered it up, it will fire up the engine only when it needs to, to top up the battery or maintain cabin temperature.

Eventually, but the amount required to keep the engine turning over in the

Just be thankful that we're not all saddled with totally electric cars. = I wouldn't want to be stuck in one of those overnight in the snow!

Tim

Don't be silly. Energy is needed to overcome the friction within the engine - as well as to drive things like the alternator, waterpump, gearbox, etc. Of course any stationary vehicle with the engine running is doing zero MPG.

I'd love to know just how its batteries perform in extreme cold. My guess is not at all.

Looks like the ice cream in my theoretical van is going to melt then. ;-)

Er, yeah, That's because they are doing 0 miles...

Chris

Or ever!

Chris

But look at the energy balance. The only possible outlet would be the battery, but if that is already full then even the alternator, like the rest, is just producing heat from friction.

Well, depends on your definition of 'extreme cold'.

They don't appear to be doing anything different in current conditions - I don't think it's an issue, as Toyota have had to fit a cooling system to the battery pack to stop it over heating.

My car (a BMW Mini) has got an override button.

Rob

You're drawing your box round too large a bit to be able to get the overall power needed to keep the engine idling.

Yes, but a diesel injects just enough fuel to keep the engine turning over whereas a petrol engine has to use enough fuel to create the correct fuel air ratio and use a throttle to regulate it. So that extra fuel means more waste heat. If the main reason you're running the engine is to keep warm that's not so bad, but as well as running the heater some of that heat escapes via the exhaust, and probably the radiator too unless it's very cold out or you switch the engine off before it fully warms up.

What about the electrical consumers? Lights, heater blower, radio, ect.

Many modern cars run the A/C in demist mode; the load there is certainly significant.

Chris