Warming up the car?

I read an article via E&T magazine the other day about the carbon cost of 'warming up the car' on winter mornings before driving off and wondered how many people still do such a thing? 

I remember in the 1970's some of our neighbours would always have their car idling for a while and vaguely remember them saying something about getting the oil circulating around the engine first before driving off. But as far as I'm aware, there is absolutely no need to do that nowadays with modern cars, if it was ever needed before anyway! The manual of my own car specifically states that it should not be started and left in an idling state but should be driven as soon as the engine is on.

Warming up the interior of my own car on a winter's morning consists of me making sure the heated seat is on (which can be felt around 2 minutes into the journey Relieved) although one thing I struggle with on occasion is de-misting the windscreen which can take longer. However I bought myself a telescopic handled de-mister pad that I wipe over the inside before I switch on the ignition.

Out of interest is it (or was it ever) necessary to idle a car before driving off? Were my 1970's neighbours correct? Thinking 

  any tips from the experts in the Automotive and road transport systems Network? 

  • certainly before fuel injection was a thing and we wereall much more adept at modulating the mixture with a combination of juggling of choke settings and throttle blipping, a lot of cars were likely to stall and not restart when cold, or at lesat require several pulls with varying settings.  A less jumpy journey ensued if it was all warmed up. Also the older engine oils (Duckhams 20W50 comes to mind) went quite treacly at low temps, so getting it thinned down a bit was wise. On older cars the oil tended to start to drip past the seals once runny and up to temperature, so you needed to be on your way before that or be prepared to clean up. At one point I had a car with a tray of sand under it for this reason ;-)

  • I've only ever owned 4 cars in my lifetime as I tend to keep them going for a very long time. My current one is now over 20 years old but to me is still relatively modern Joy But yes my first two cars had a choke that had to be juggled to get it just at the right setting to get the car going but not flood it! 

  • Choke? Luxury, you were lucky t'have choke. I had a Mk III Escort with an automatic choke. If it didn't start first time best thing to do was go back inside and have a cup of tea while it sorted it self out. I quickly replaced it with a manual choke convertor kit, the guy at the Ford dealers said "we sell a lot of these..."

    I used to have a different issue (given we live somewhere very damp) where on winter's mornings, if I hadn't had the engine and heater running to warm the windscreen up, the damp air would hit the windscreen and condense / freeze just at the point at the end of the road where I headed South East into the sun. I solved that one by taking a job where I worked from home!

  • If you've got a car with working aircon, turn that on as well as turning the heater up to maximum.  It demists the windscreen a lot quicker.

  • I am told that oil pumps in modern engines raise the pressure almost instantaneously, but they took a little while in old cars. Compared with the past, modern engine oils are very thin so they will circulate more readily too.

    Occasionally in winter, I have to wait for the screen to demist too. Quite why Ford has kept heated front screens to itself is a mystery, but they are superb.

    This is what the instruction book for my 1931 R-R says.

    The engine should be allowed to run for a few minutes before taking the car on the road, during which it should be noticed that the oil pressure is registering between 20 to 30 lbs. The car should not be driven hard, however, until the water temperature has reached 60° C.

    In fact the oil which I use (10 - 60W) takes only about 20 sec to reach full pressure. In practice, by the time that I have got the car out of the garage, closed the garage doors, driven into the road, and closed the gates, enough time has elapsed to be able to set off straightaway.

  • Quite why Ford has kept heated front screens to itself is a mystery, but they are superb.

    Agree Chris. My wife was gutted to learn she couldn't have heated front screens, having had them for years on various Fiestas.

    Imagine the future though, you see the weather outside, click on your phone, the car heats up while you sip your morning coffee and then you climb into a lovely warm, defrosted car ready to go. Oh sorry, no that's today for some ;-)

  • no need for conversion to a manual choke. My first car was a beetle with a Solex carb and auto-choke which didn't work. Instead of all the effort of converting to manual or repairing it, I used to carry a bottle of petrol and empty on capful of petrol through the air filter for cold -starting!

  • Quite why Ford has kept heated front screens to itself is a mystery, but they are superb.

    My other half has a Ford van with a heated front windscreen and as you say Chris, it is superb. I do find it a bit weird as from time to time my eyes will focus on the thin wires sandwiched between the glass, especially in the summer if the light is in the right direction. Not while I'm driving though I hasten to add! 


    Please stop making me feel old.

    When I was a kid my dad had an A35 van converted to an estate car with a folding rear bench seat and windows cut into the rear side panels.

    It was kept in a garage with a sump heater under it over the winter, then coaxed into life in the morning with careful manipulation of the choke.

    I remember staying at my Grandparents one Christmas and it spent a couple of nights outdoors, it failed to start and flooded, so my dad had to take the spark plugs out and heat them in the oven to dry them off and heat them up.


    It was common practice to run the engine until the choke could be pushed in before driving off and to completely clear the windows of ice to ensure full visibility, these days people just jump into their vehicles and expect to drive off immediately without even clearing the windows, like the girl who pulled out in front of me this morning.

  • Don't worry about the carbon cost, there is no direct CO2 charging infrastructure created yet, though Al Gore is developing an app. So not long now before we are all charged for breathing.

    Anyway while your car warms you'll be contributing to the the greening of the planet to help feed the new 8 billion population