You need the engine to run for a bit so the heating matrix warms up allowing the windscreen to demist, you can't very well go driving off if you can't see.
You monster! Think of the poor little fluffeh kittehs that will choke on your exhaust fumes, just because you can't be arsed to lean forward and wipe the screen!
If it's frosty, I'll start the car before setting to with the ice scraper, mostly so I can warm my hands on the vents when I'm done but otherwise? Just have a decent, clean cloth in the door pocket, Shirley?
Your point about coasting to save fuel falls down on two counts. Firstly, as has been pointed out already, in a modern engine, taking your foot off the gas shuts off the fuel injection unless the ISCV (Idle Speed Control Valve for those who don't speak car) detects the engine slowing below it's idle point.
Secondly, and this may just be since I recently trained as an HGV driver, and had it drilled into me (fnar fnar), but you should NEVER EVER COAST, EVER! Especially down hill. The only time your foot should be on the clutch while moving is when changing gear, setting off or coming to a stop, otherwise you're not in complete control of the vehicle.
My instructor was very keen about this, and it holds true. Ever gone to change down on a gradient and missed the gear? It's surprising how quickly the speed builds up if you're momentarily distracted. If you're in the right gear, the engine braking is doing a good deal of the job of maintaining a steady speed for you.
The thing about engine braking is to use it, but don't change down until you've slowed down a bit. I was taught that 'Brakes are for slowing, gears are for going.' Iow, take foot off gas first, brakes if necessary, go for a lower gear when the engine gets to just above idle speed, before it starts driving you on.
Sorry, I seem to have gone off on one there. I wasn't trying to be a smart arse, though I'm sure that's how it appears!
(Hairy Bob, Fri 14 Jan 2011, 11:38, Reply)