Does anyone know the fuel consumption per hour when idling a 2016 Honda 2.4 Liter Earth Dreams engine?

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4,856
Location
Pittsburgh,PA U.S.A.
Hi fellow BITOG People, I posted something along these lines on the Honda CR-V owners forum, but so far there are no direct answers.

I am wondering what the fuel consumption per hour would be for idling a 2016 Honda CR-V 2.4 Liter direct injected normally aspirated Earth Dreams 4 cylinder engine when the engine is already warmed up? Just to keep heat in the cabin of the vehicle in winter conditions such as if you were on a major highway and the highway was shut down due to something like a huge winter storm, or a big rig accident, and you were stuck there for hours or even over night?

I am not talking about fuel consumption during idling while warming up an engine. I know that is more because a cold engine must be ran with a rich mixture. I am looking for the fuel consumption per hour for running an engine that is already warmed up?

I looked on some internet sites for information on fuel consumption during idling and could not find anything specific to that engine. But I did find one site that listed idling consumption vs engine displacement. On that site the closest size to 2.4 Liters was 2.0 Liters and extrapolating that to 2.4 Liters shows an hourly fuel consumption of 0.192 gallons per hour. I am wondering if it could really be that low?

I know Honda made the 2.4 Liter for a long time and Honda makes good engines. And the latest version Earth Dreams model is a very efficient engine that has variable valves, direct injection, and low friction pistons, among other things.

I am wondering if anyone has information on the actual fuel consumption per hour when idling in winter conditions in park for this engine?

If it were really around 0.2 gallons per hour and you had a decent amount of gas in the tank, you could probably easily idle all night and more and still have enough gas to go when things got moving again.

Also, as an additional piece of information, it would be nice to know the fuel consumption per hour when idling in hot summer conditions with the AC on max?

If this information is not available, then it would be nice to know if some scan gauges show the fuel consumption per hour based on the data from the vehicles sensors? And if so, which ones?

The MPG calculator in my CR-V is fairly accurate. I get between 21.2 MPG to 22.6 MPG actual, driving the roads around the south hills of Pittsburgh, calculated based on miles and how much it takes to fill the tank. And the indicated is always 0.1 or 0.2 MPG more (optimistic) then actual, so that is within 1%. Not bad, and if the flow rate of the sensor the vehicle uses could be read on a scan tool, then that information should be within that same error range.

It sure would be nice to find out without having to filling it up, run it for something like 5 hours at idle, and then refill, just to find out what the numbers are. Though that may be the only way to get the answers.

Thanks in advance for any information.
 
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1,931
Location
Cincinnati, USA
This is ridiculous. The amount of fuel used is trivial and worth less than our time answering.

You don't need the vehicle to warm up without reason but if there is ice on the windshield, it's prudent to warm it up. Don't ask about trivia otherwise when it is obvious that not running it uses less fuel than running it, so there is some reason to do it.

I know you talked about being stuck, but no. If that is a serious concern then you have additional winter coat and/or blankets. It is not rocket science. If you feel you might have to hike out then you have winter boots, food and water too. This is not a new thing, not some question that needs asked today, has been the same situation for winter that humans faced for centuries. No?
 
Messages
339
Location
WA
.15 gallon / hour
with A/C load max it's .33 gallon / hour but you'd recirculate the air & get too cold & back off from max output, right?
& I won't share my computation formula . : l
 
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52
Since you say your car has an accurate mpg meter, you can use the mpg meter and your speedometer to make a back door calculation of fuel burned per hour which should be fairly accurate. Find an empty straight stretch of road somewhere where you won't get rear ended, (I use our subdivision for this) and at about 30 mph slip the transmission into neutral. Let the engine engine idle down and as the car coasts down in speed, watch the mpg meter. When the mpg's drift down into the "believable" range, say 40 to 60 mpg, note the mpg number and your speed. The mpg divided by the mph gives the hours it will take to burn a gallon of fuel. The inverse of that, mph/mpg, is the gallons per hour. I've tried that method with both our V6 cars and get an estimated idle time of 1.5 hrs on a gallon of gas with the A/C on, about 2 hours with the A/C off. I would guess a 4 cylinder would beat that by quite a bit with the A/C off, maybe not so much with A/C on.
 
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2,400
Location
Pennsylvania
Interesting question that should be considered by anyone who may have to evacuate in a hurry. Fires in the west, hurricanes in the south and along the east coast, etc. An obvious statement is that if you are worried about being in a situation with long idle times, you should keep your tanks filled and perhaps a SAFETY can of fuel in the car during those times of the year when you might need it.
 
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1,676
Location
Winnipeg MB CA
For comparison purposes, our 2009 Mazda 5's 2.3 l (2261 cc) engine uses as little as 0.7 l/hr at idle. That's warmed up, in N, in non-winter conditions, and without running accessories. Consumption is higher in the winter, higher idling with AC on, and much higher during warm-up. Our car is manual, but consumption would be higher with an AT in gear. (Consumption is per my ScanGauge.)

That works out to about 0.2 US gallons/hr, or about 1 US gallon in 5 hours.

So, a full tank should allow you to idle for a long time.
 
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2,475
Location
Deep in the heart of Jersey
It seems to me that when your car is idling, that's the easiest service the motor can ever see. It just needs enough fuel to keep the pistons moving up and down in the cylinder. That's why you get you don't use much gas when idling. I don't get these new cars that shut the gas motor off at lights or in traffic. To me the only benefit I see from doing that is part sellers, will be selling more starters, alternators, and batteries. Being stuck in miles of stop and go traffic has got to eat up the starting systems. I would always be thinking about how many starts the battery has left in it. Wouldn't you think the rebuilding / reclaiming process of those parts, would create more pollution then using a very small amount of fuel?
 
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10,329
Location
Jupiter, Florida
Many vehicles will
run or cycle the compressor with the heat on. Even if it is selected off. My 2018 F150 2.7L will run the compressor upon startup and at random times, even with the compressor selected off and vent selected.

if your car does this, the fuel use will vary.
 

JTK

Messages
13,239
Location
Buffalo, NY
Yeah, our 2019 Nissan Pathfinder cycles the compressor and cooling fans at low speed with any/all HVAC mode selected.

So flipping annoying when you start it in extreme winter cold and you hear it at least trying to cycle and the cooling fans blowing away on an ice cold engine.

To me, I'd find it hard to believe even a present day 4-banger would only use a gallon of fuel with 5hrs of idle time. That would be like 50+ hrs of idle time on a full tank.

Those Honda DI 4cyls would fill the crankcase with fuel in that time. Kidding..
 
Messages
455
Location
Virginia, USA
.15 gallon / hour
with A/C load max it's .33 gallon / hour but you'd recirculate the air & get too cold & back off from max output, right?
& I won't share my computation formula . : l
That looks about right. During hurricane Sandy, my Subaru idled got 33 hours to run a small inverter for our sump pump and refrigerator; it used 5.757 gallons (including the 3.4 miles round trip to the gas station) which comes out to 0.174 gallons per hour. Boxer engines are a tad less efficient than an in-line 4 so 0.15 gallons per hour is believable.
 
Messages
290
Location
TX
In contrast I saw in my manual for my 1200cc turbo Honda Aquatrax jetski making 165hp-consumes 14 gal/hour! 64 GPS mph! We rarely use 1/2 tank (17 gal tank) in the 2-3 hours we run them in a day. Amazing fuel mileage for what it can do, if you stay out of it some of the time! You can cover a lot of river at 64.....
 

JimPghPA

Thread starter
Messages
4,856
Location
Pittsburgh,PA U.S.A.
This is ridiculous. The amount of fuel used is trivial and worth less than our time answering.

You don't need the vehicle to warm up without reason but if there is ice on the windshield, it's prudent to warm it up. Don't ask about trivia otherwise when it is obvious that not running it uses less fuel than running it, so there is some reason to do it.

I know you talked about being stuck, but no. If that is a serious concern then you have additional winter coat and/or blankets. It is not rocket science. If you feel you might have to hike out then you have winter boots, food and water too. This is not a new thing, not some question that needs asked today, has been the same situation for winter that humans faced for centuries. No?

The snow belt north of I 80 on 79 below Erie is notorious for bad winter storms and whiteout conditions. We use to travel that for hunting in the winter and back then it was a no brainer that the 350 8 cylinder Chevy engine in out station wagon would drink way too much fuel to even think of running the engine for heat if you were ever stuck over-night somewhere. We did bring sleeping bags even it we were staying at a cabin.

About 20 years ago my sister and her husband went to Erie for a good job interview for my sister when he was laid off. On the way back they got hit with a major snow storm. They had a heck of a hard time finding a hotel because everyone was giving up the idea of continuing on there drive and the hotels were all filled up. They got lucky and found one, but they had to travel some more on the highway to get to it.

I was in a bad snow storm in the day time up there once and on for one stretch of road the snow drifts totally covered up any signs of where the road was. The only thing I had to go by was a highway overpass way far ahead that I could make out and I knew the road had to go under the right side of the overpass and aimed the car for that and managed to stay on the road even though I could not see where the road was.

At night those winter white-outs are really scary. You can't see if there is a vehicle stopped in-front of you, and you are afraid to stop or go too slow because a big rig might hit you. And even if you pull over a big rig might also decide to pull over and not see you there. And you can get stuck on exit ramps.

Once you experience those conditions you learn to pay attention to weather reports and NEVER let that happen again.

But sometimes interstates do get shut down when you are not expecting it. And I thought the information about the very low fuel consumption per hour of idling for modern engines is almost be not believable.

It is nice to know that if you had to, you could idle the engine for heat for a long time with some of todays modern engines.
 

JimPghPA

Thread starter
Messages
4,856
Location
Pittsburgh,PA U.S.A.
Many vehicles will
run or cycle the compressor with the heat on. Even if it is selected off. My 2018 F150 2.7L will run the compressor upon startup and at random times, even with the compressor selected off and vent selected.

if your car does this, the fuel use will vary.

^ I can see a vehicle cycling the AC compressor on to dehumidify the air if defrost is selected, such as to defrost the windshield. But it does not make any sense for a vehicle to do that if heat is selected and nothing regarding defrost is selected.

If I had a vehicle that ran the compressor when I was selecting heat (without defrost) I would add a switch in series with the wire for power to the electric clutch of the compressor, so I could disable it from doing that.
 
Messages
2,187
Location
Arizona
If I was truly concerned about emergency prep and I didn’t have a ScanGauge (which I do), I’d figure on 1/2 a gallon per hour, but hope to burn half that (or less?). Hard to tell about idling on the side of the road all night in a blizzard, though.
 
Messages
2,666
Location
Kansas City
When I had the 4 Cyl Tacoma it had an UltraGauge. When you went under 10 gal of fuel, the display went to showing 1/100 of galllons (ie 9.99)

When warm at long red lights it would show that 1/100 of a gal was used every 90 sec or so. That Honda should be in the same ball park. It was a manual and at long lights I was usually in neutral with brake applied.
 
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Messages
1,087
Location
Minneapolis
if it's freezing enough, the engine won't stay at operating temp while idling and heating the cabin so fuel consumption will be higher.
This.

During our little blizzard yesterday, I stopped in a parking lot to make a 20 minute phone call. I was idling the whole time and the temp was about 10F with 30-40mph winds.

Over the course of the call the oil temp fell from 220 to 190F. Once I started driving moderately it popped back up.

My old diesel equipment would easily cool off completely idling with the heat on.
 
Messages
708
Location
MO
I can’t remember what vehicle it was but my scan gauge would show .2 gph at idle. That might’ve been an 06 VW TDI but at least gives you and idea.
 
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