How much fuel does idleing use?

[rusty ol ranger]

I know you use more gas in cold weather anyways but....it ive been letting my 2.9 warm up 10-15 min in the morning and it seems like its chewing thru alot more fuel then it should be even taking the idleing into account.

Nothing points to a problem im just curious.

 

[fastpakr]

Very little - I suspect you could idle for a couple of days on a tank of gas.

 

[sgtsandman]

I remember someone quoting a usage amount at one time but I can’t remember what it was. It was pretty low though. I suspect fastpakr is correct.

 

[bobbywalter]

There are formulas.


But actual gas formulation is critical....

E gas sux.

The difference between e15 and regular real gas in winter was 25 to 35 percent in economy on my 3.3 Chrysler in winter..

It's stupid

 

[rusty ol ranger]

So its probably in my head. I figured it didnt use much.

 

[Blmpkn]

I've heard/read it can be up to a 1/4 gallon every 15 minutes.

 

[PetroleumJunkie412]

Ehhhhh..... my 2.9 used an unreasonable amount of fuel idling in winter on the factory ecm. Like... more than my SOHC uses.

Always thought it was weird.

 

[gw33gp]

I've heard/read it can be up to a 1/4 gallon every 15 minutes.

That seems excessive. My Ranger uses less than one gallon on my trip to work which takes about 20 minutes. That is about half stop and go and the rest at around 80 mph. I can't believe idling would consume more than 1/4 of the fuel it takes for my trip to work. I don't have a better answer for idle fuel consumption though.

 

[sgtsandman]

I believe it was more along the lines of a tenth of a gallon of gallon an hour. The efficiency of the engine and the number of cylinders plays into to that as well.

 

[97RangerXLT]

I warm my Buick up every day when the weather is under 32 degrees. the remote start will run the car for 10 minutes then shut off if you don't put the key in and turn it on and drive it. my fuel economy went from about 320 miles per tank to anywhere from 245 miles to 260... at this point I am wondering if my Ranger is more fuel efficient...

AJ

 

[sgtsandman]

Block heater and oil pan heater. Run up your electric bill instead. The tree huggers seem to think it’s a better solution than burning fuel in your immediate vicinity...

 

[rusty ol ranger]

My odometer dont work so i can *accurately* check my MPG but i seem to average 19-21 depending on what im doing (estimating mileage off google maps).

Just seems my gauge drops faster now. Even though it wasnt super accurate ever. I filled up tuesday and its showing under 1/2 (probably closer to 3/4 real level) after probably roughly 80-100 mi of driving.

Well...i guess even at 80miles and 4.25 gallons (17/4) thats 18.8.

Guess im still in the neighboorhood.

 

[sgtsandman]

The cold weather has taken a hit on mine. I went from about 18 to about 15+ and I don’t warm the truck up. That is even with the winter fuel knocking the average down. No sir, Mr. Horse is not liking it one bit.

 

[RonD]

What do spark plug tips look like?
Pull a few and see, should be very light brown on white electrodes

If its darker then engine is running richer than needed, could be older O2 sensor, they do false leans as they age

Idle is actually a richer mix so engine doesn't overheat, and to get and keep Cats HOT

Cold start also has Choke Mode so first 5 minutes or so uses twice the fuel as warm idle will

ECT sensor sets and removes Choke Mode based on coolant/engine temp, so the faster the warm up the lower the fuel usage
And that brings in the "air pre-heater" system that is usually removed in older vehicles, lol

Pretty much all vehicles have an air pre-heater system from the factory, it will have a "chamber" around exhaust manifold that gets pre-heated air inside instantly after engine starts
And an air hose/tube from that "chamber" to the air intake for the engine
There is a vacuum operated diverter valve that pulls in the pre-heated air when engine is cold
This shortens warm up time by a few minutes so shorter Choke time, less fuel used
Also lower emissions because of shorter warm up time, so required in places like Calif.

The vacuum air diverter valve/flap is operated by a non-powered thermal vacuum valve usually on air cleaner box
In colder temps this thermal valve is open, so when engine starts vacuum is sent to diverter valve and pre-heated air comes in to the engine
As the pre-heated air warms up the engine, and the air filter box, this thermal valve slowly closes, as does diverter valve and "fresh air" is used

 

[scotts90ranger]

Cold temps drop my '97 even, the stupid thing over cools like heck around freezing... colder temps is more air per volume (higher density) and in open loop fueling (IE not warmed up) it's going to be rich to start with... last summer I got 24mpg in the '97 and now it's getting 21 if it's cold consistently...