Leaving the car running or turning the engine off ?

[richard bf]

Hi guys another post from myself ...


Does leaving the car running for say 5 or so minutes whilst you nip into the house use more petrol than stopping and starting the car ? im under the illusion that its better to leave the car running if its for a few minutes as opposed to stopping and starting the car all the time .

Can anyone shed any light into this ?

Ta Rich.

[ShayneJ]

[twazzock]

Leaving the engine running burns oxygen from the atmosphere, which reduces the oxygen available and increases air pressure, forcing air into your engine (like a supercharger) and increasing engine efficiency. In answer to your question: kippers.

[TAHodgson]

If it's first thing in the morning, I tend to leave the car in the garage running for 5 mins or so before I leave, just so it can warm up a bit before I start going through the revs. I wouldn't of thought it uses much fuel to be honest...

[anonymous-user]

Why would the car burn lots of fuel when you simply start it up?! It's not a bloody steam engine is it?

[Fox-]

I find my car uses less petrol when it's parked outside with the engine off than it does when the engine is on. How odd. Infact I've got a feeling that when the engine is off it doesnt use any petrol at all!

[rumbletum]

Well, the fact that many car manufacturers are introducing auto stop/start functions in their cars for environmental reasons kinda answers your question.

[anonymous-user]

Fox- said:

I find my car uses less petrol when it's parked outside with the engine off than it does when the engine is on. How odd. Infact I've got a feeling that when the engine is off it doesnt use any petrol at all!

[Deva Link]

richard bf said:

Does leaving the car running for say 5 or so minutes whilst you nip into the house use more petrol than stopping and starting the car ? im under the illusion that its better to leave the car running if its for a few minutes as opposed to stopping and starting the car all the time .

Can anyone shed any light into this ?

BMW say about their stop/start system that the break-even time is 2 seconds.

[Mr Gearchange]

It's negligable.

Any savings you make in petrol will be offset by someone nicking your car which is sat running with the keys in the ignition outside your house.

[paps]

the only advantage to leaving the engine running is that saves a little wear and tear om the starter motor. but you'll save fuel by turning the engine off.

[Leptons]

richard bf said:

Hi guys another post from myself ...


Does leaving the car running for say 5 or so minutes whilst you nip into the house use more petrol than stopping and starting the car ? im under the illusion that its better to leave the car running if its for a few minutes as opposed to stopping and starting the car all the time .

Can anyone shed any light into this ?

Ta Rich.

It's relative.

[checkmate91]

It's also not good practice to leave a running vehicle unattended (I may have used a euphemism).

[pops and bangs]

The obsession with mpg is getting ridiculous...

For gods sake there was a guy the other day asking whether taking his shoes off would increase his mpg...

[stoocake]

pops and bangs said:

For gods sake there was a guy the other day asking whether taking his shoes off would increase his mpg...

And does it???????

[chunkol]

Don't these new cars that do the stop start thing at traffic lights etc. show a saving on fuel? Presumably, the bigger the engine, the better the saving. I'd suggest a 20 litre Merlin engine with stop start technology would be amazingly frugal. The downside is the aircon would stop working at rest.

[pops and bangs]

stoocake said:

And does it???????

Apparently it does, someone said that not only do you have "teh ultimate weight savinnggzzz" but it allows more subtle throttle adjustments.

[Olivera]

TAHodgson said:

If it's first thing in the morning, I tend to leave the car in the garage running for 5 mins or so before I leave, just so it can warm up a bit before I start going through the revs. I wouldn't of thought it uses much fuel to be honest...

That technique causes more wear and tear, and fuel than just getting in a driving it gently from cold.

[paintman]

richard bf said:

Hi guys another post from myself ...


Does leaving the car running for say 5 or so minutes whilst you nip into the house use more petrol than stopping and starting the car ? im under the illusion that its better to leave the car running if its for a few minutes as opposed to stopping and starting the car all the time .

Can anyone shed any light into this ?

Ta Rich.

If you do it on your drive you're likely to come back out & find the car missing - and I don't mean mis-firing

[pops and bangs]

richard bf said:

Does leaving the car running for say 5 or so minutes whilst you nip into the house.....im under the illusion that its better to leave the car running if its for a few minutes

Can anyone shed any light into this ?

Ta Rich.

One thing's for certain your insurance won't pay out if it's stolen....