petrol when car not moving

Are you serious ? I smell a troll

Dave

If the engine is running then it's using petrol (unless it's a diesel or LPG or electric) even if ther car is stationary.

The starter doesn't use petrol but as soon as you turn the engine it starts to use petrol (let's call it *fuel* as that covers everything).

Rob Graham

seriously I was told when I was having lessons by my adi that its uses a very miniscule? amount

not a troll just a regular clueless poster

mocha wrote on Thu, 19 Jan 2006 18:31:44 +0000 (UTC):

Well, there's your answer.

If you know it uses a very miniscule amount, why ask if it uses ANY?

Perhaps a better question would be how much petrol it uses. That, I don't know, although it seems obvious it would take significantly less petrol to produce enough energy to idle an engine, clutch and gearbox input shaft than to spin the engine at 4,000+ rpm along with clutch, gearbox input and output, and the wheels, which will be pushing against air resistance, etc.

"mocha" wrote in news:dqolug$lrg$ snipped-for-privacy@nwrdmz02.dmz.ncs.ea.ibs-infra.bt.com:

ISTR reading that 3 minutes of idling used enough fuel for a mile of driving. This is obviously a very rough guide, as the amount used while driving varies according to the speed.

The message from "mocha" contains these words:

If the engine's running, then yes. In fact you're doing zero mpg.

Yes - loads on a cold petrol engine. The difference with diesel is less clearcut, though there is some increase particularly when idling cold.

If the engine is stopped, then no, even if the car is moving (think about it) :-)

Again think it through!

I asked because I didn't know if my instructor was taking the mick or being serious as he laughed when he said it and wasn ot the most serious off people.

hence why I asked in here.

mocha wrote on Thu, 19 Jan 2006 19:09:08 +0000 (UTC):

Well OK, I just don't see why the question changed from "does it use very little fuel" to "does it use fuel".

Basically, with fuel injection your car will be using fuel whenever the ECU is injecting it. It'll do that to keep the car from stalling, or if you're trying to accellerate. If you're on overrun downhill though, it might not need to use any petrol.

When you're starting the car, it'll start to use fuel at some point. With fuel injection, that point would be when the ECU decides to start firing the injectors, probably after it sees some number of revolutions of the crank/cam shaft.

Ok. Thank you for explaining it to me. Much appreciated.

Conor wrote in news: snipped-for-privacy@news.individual.net:

So, assuming that your trip computer and my theory (wherever I got it from) are both correct, your lorry is capable of 91mpg ;-)

Hmmmm......I have a strong feeling that the theory is a load of b****cks, at least where wagons are concerned :-)

If the engine is running it uses fuel. There are some vehicles that have a system that stops the engine when stationary, but these are very rare.

mrcheerful

My Rover definitely uses a little petrol when it is standing still with the engine stopped, it drips past the seal between enrichment device and mixture adjusting nut on the SU carb or evaporates out of the float chamber. lol

Fortunately the SU pump tops everything up on the turn of the key and I can then start engine on the starter button

I have to wait for my mechanical pump to top the carbs up before the engine'll fire. On the bright side that means there's a short time of cranking for the oil pressure to start building up I suppose. Maybe I ought to sort the carbs out, but then I'll have to do the bearings all the sooner...