How much fuel does a car use for ignition?

therealnerd2 said:
Not convinced myself. IMHO an idling engine @ 1k revs is going to warm up at close to the same rate as one at 2k revs - however at 2k revs there would be more potential for damage.
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you are wrong, leaving an engine idling to warm up is not the best way to do. pretty sure race engines are started and then revved quite high to warm them up.
 
Bes said:
My brother (who is a qualified mechanic) reckons it is about the equivalent of 3 miles worth of driving for an average (i.e.1.6 or so) car.
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:eek: wow. that kind of makes sense I've been doing a lot of stop start driving this week and noticed I got around 20 miles less than my normal average week usage. There is a possibility there is other factors aswell that we have to consider..
 
therealnerd2 said:
Not convinced myself. IMHO an idling engine @ 1k revs is going to warm up at close to the same rate as one at 2k revs - however at 2k revs there would be more potential for damage.
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An idling engine takes agesss to warm up. A driving engine takes maybe 3-4 minutes? 3-4 minutes of easy driving gives less wear than leaving a cold engine for 10 minutes at 1krpm to warm up slowly.
 
fwiw my colt idles at 2000rpm from a cold start, it does this by design to warm the engine up quicker. My usual procedure is to reverse it out of the garage (have to weave between 2 other cars to do this mind), get out and close up the garage and turn the lights out, and by the time I get back in the car and belt up it's usually down to about 1500 and the temp gauge is moving up, this takes no longer than 90s so it seems like a good system.
 
Thankfully mine takes a few minutes to heat up which is good considering in these winter months I want that heater warming me up ASAP :p.

Shame as soon as I arrive at college I don't want to get out the car as it's lovely and toasty :p
 
GeX said:
you are wrong, leaving an engine idling to warm up is not the best way to do. pretty sure race engines are started and then revved quite high to warm them up.
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If I did that on mine Im sure something would break very quickly.
 
Tom|Nbk said:
Was just about to say why complicate things :p, I just want to know the typical amount burnt on ignition.
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Right, which is what I answered. Ignition is is an event that occurs once in the 4 cycles of your engine. If you want to know how much fuel is used when starting the engine, then ask that.
 
According to an american aero-engine maintenance handbook I've temporarily chavved from the local flying club it says that the best way to wreck piston engines is to thrash them from cold.

It reckons that every component is designed for a normal operating temperature range and that the engine should be started and left to idle at 1200 for a time proportional to the ambient temperature. The colder the longer etc.

This allows every component from valves to seals to crankcase to gears to drive belts etc to absorb heat gradually which in theory reduces thermal cycle damage (cracking, thermal shock, etc) and prevents rapid wear all of which by all accounts shorten the engine's life and reduce it's performance dramatically.

It also suggests allowing the engine and associated components to cool down after high power operation. Must be true because even the big jets follow the same procedure. Could be BS but I'll stick wit the heat sink theory and save on engine repairs, head gaskets etc...
 
According to an american aero-engine maintenance handbook I've temporarily chavved from the local flying club it says that the best way to wreck piston engines is to thrash them from cold.
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Thats true for any engine :S Thing is with an aeroplane you need max power to take off, you dont need maximum power to get to 30mph on the way to work.

Basic idling is a good to check to ensure the engine will fuel correctly at operating temperature, rolling to a stop on the hard shoulder is not quite possible in an aeroplane hence the warm up and the damage of cold idling is less than a full throttle take off to climb an aircraft, hence the warm up. Most airframe components have shorter operating lifes than the engine, so theres no real merit.

Don't even compare internal combustion engines to any sort of gas turbine, there is no comparison the temperatures in those would melt a car engine into a puddle.
 
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GeX said:
they're designed to warm the cat up ASAP which is why they put them so close to the manifolds now.
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hence the utterly pointless secondary air pumps.

the only reason a cold engine drinks more fuel is condensation, more fuel is needed to overcome what has been lost when it condensed on everything cold it hit on the way. aside from occasionally missing a part of the suck, squash, bang, blow sequence starting a car from hot doesn't drink that much more fuel any more. not like they used too anyway when the ecu would get the injectors going overtime for as long as possible.

there is only one reason we are driving cars with advanced ecu's and fancy mpi systems and it has nothing to do with power or smoothness, 99% of a ecu's work is controlling emissions.
 
dalin80 said:
hence the utterly pointless secondary air pumps.

the only reason a cold engine drinks more fuel is condensation, more fuel is needed to overcome what has been lost when it condensed on everything cold it hit on the way. aside from occasionally missing a part of the suck, squash, bang, blow sequence starting a car from hot doesn't drink that much more fuel any more. not like they used too anyway when the ecu would get the injectors going overtime for as long as possible.

there is only one reason we are driving cars with advanced ecu's and fancy mpi systems and it has nothing to do with power or smoothness, 99% of a ecu's work is controlling emissions.
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What are you on about.

Secondary air injection systems are not pointless.

CBA to write that much, but I wanna see you get an engine close to a ECU controlled engine with just carbs. Good luck!
 
i don't know what you mean, mechanical and vacuum advance units are a much better way of controlling ignition timing than completely tuneable table based on manifold pressure, revs, temperature etc.
 
dalin80 said:
hence the utterly pointless secondary air pumps.

the only reason a cold engine drinks more fuel is condensation, more fuel is needed to overcome what has been lost when it condensed on everything cold it hit on the way.
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Do you not think the friction of the cold oil has a significant effect?
 
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