It's freezing

[codswallop]

As an OAP I don't have to use my car every day,but during this prolonged very cold spell that's forecast is there any benefit in starting my car each day just to let the engine warm up.Or would then leaving it, to get cold again for a long spell do more harm than good???? Thanks!!!

[logic]

No,
It would do more harm than good unless you were going to run it for an hour or so.

[Iggle Piggle]

Hello.
Starting the car each day would give no benefit apart from keeping the battery charged, and to keep it charged, the car would have to be run for at least half an hour to put back what is drained out for an engine start.
If you can, connect a battery charger instead for a sure start on a cold morning.
Hope this helps.

[codswallop]

Thank you both for your quick replies,as my post suggested I wasn't sure whether a "warm up" was a good idea.

[KARL]

Not meaning to quibble, I would still like to examine the replies you received. Assuming you have a fairly average type of car, then the starting current drawn would certainly be less than 30 amperes and it is not unrealistic to assume the car will start within 5 seconds. That means you draw at very most 150 ampereseconds of energy from the battery in order to start the engine. I would further think the alternator will recharge at very least at a rate of 2 amperes - from the moment the engine starts (and continuously thereafter). Thus, unless I am off my rocker, the draw-down for starting will have been replaced within three minutes (almost certainly well under that). Actually, all batteries fade even during disconnected storage, not to mention when powering all the stand-by stuff in modern cars (clocks, radio settings, immobilisers, anti-theft devices, etc., etc.) so your battery will definitely be less well prepared for a start-up as time passes since the engine last ran. Add to that the likelihood that the expected eventual start-up will take place in cold weather when electrolytic reactions are slower, then you would be correct to consider an occasional start-up just to top up the battery's energy level. A 10 minute warm-up idling would, in my opinion do nothing but good, especially if your battery is less than very recent (they all lose the capacity to hold a charge and eventually fail) in which case it could mean the difference between starting and not at all. The issue of engine wear is another matter entirely but (again in my opinion) a lesser concern in anything but the long term.

[Panic Button]

I cannot quote hard facts to back this up, but I doubt if an engine on tickover produces much spare electricity to recharge the battery Karl.

I think the car would have to be driven at higher revs to generate sufficient power. Putting on the heated rear window and headlights would probably soak most of this up too.

I think Iggle Piggle's suggestion of a battery charger is the way to go.

[KARL]

If a battery charger is to hand fine, the vast majority of people do not have one nor are they inclined to buy one just in case they might need one one day. Unless the electrics are faulty, any engine in a modern car will charge up a battery at idling speed even if you have things switched on. In the days of dynamos it was a different story.

[Panic Button]

I bow to your superior knowledge.

[codswallop]

Wow!!! I've opened up a can of worms there!! You all have given good arguments for and against the occasional warm up.It seems tossing a coin is my best bet now.
Thanks again...................I think I'll go for the warm up (it was heads)

[Iggle Piggle]

Spot on mdoo98, like short journeys, short engine runs are likely to cause long term problems if the engine is not allowed to come to full temperature each time. If it does reach full temperature, thats a different story but that also increases the risk of the car being stolen while running, and the exhaust fumes created.
If the car is run on a decent journey once a week, that is all that is required.

[R1Geezer]

Mayo is caused by a head gaskett problem.

To answer the question you should not start every day, possibly once a week and run for long enough to get properly warm, if you are using it within a week then don't bother, just make sure you have anti freeze!