How many gallons per hour at idle???

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dualsport
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How many gallons per hour at idle???

Post by dualsport »

Hey guys... We have a lot of time at idle to warm our vehicles up here and my question is: "How many gallons per hour do our pickups burn?" (assuming we're all running with the 4.3l v6)

I'm sure running the defrost burns more fuel too... Hmmm...

I'm sure someone out there has an answer or an educated guesstimate :)

Thanks!
2001 Sonoma CC, TB crank, 2" shackles, 2" BL, Helper Springs, 1.25/2.5 Spacers, 31" BFG ATs, Quadbeams, messed up 4wd switch :) miscellaneous squeaks and pings...
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Re: How many gallons per hour at idle???

Post by HenryJ »

Use and engine block and cabin heaters. Saves a bunch of fuel.

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Re: How many gallons per hour at idle???

Post by dualsport »

weeellll...

we're talkin about a vehicle sitting outside at -40 to -50 for twelve hours at a time between starts (overnight). i'm using a block heater, oil pan heater, tranny heater, battery heater, etc, etc... :) i've got our rigs plugged into timers and ran a separate circuit for the cars outside... but that's just so it'll start half decent- i still have to run it for the temp to rise at all. heck, sometimes i have to drive slowly for the first mile till the flat spot on the tire rounds out again :) you never knew you had so much loose stuff in your rig until it's bouncing around like that!

so back to the question- it comes from when i'm at the pump filling up and i do a quick *gulp* at my 10-12 mpg calculation... but it's real hard to not count on those warm-up times and those times when i've left the rig idling in the driveway of a buddy's house, etc... These winters are just plain hard on a vehicle, and especially hard on mpg. we're expecting -35 tonight, so it's got me thinking about it again.

Anyway... all that to say, "Anybody know the gph on these 4.3's?" :) Would a scanguage II report anything like that?!?!

Thanks guys...
2001 Sonoma CC, TB crank, 2" shackles, 2" BL, Helper Springs, 1.25/2.5 Spacers, 31" BFG ATs, Quadbeams, messed up 4wd switch :) miscellaneous squeaks and pings...
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Re: How many gallons per hour at idle???

Post by HenryJ »

Cabin heater...

No waiting for it to warm inside. It is warm already. Windows defrosted. The only issue that I have had with that is when I set the temperature too low and we had a foot of snow over night in very cold conditions. Ice build up on the doors took a little work to get into the truck.

I don't have a good figure. You will have to give us the difference between summer (no warm-up) and winter (warm up) figures. You might consider that 10% of that reduction in mileage could be due to a winter grade of fuel too.

ScanguageII does show fuel rate and fuel economy. I have not watched the fuel rate.

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Re: How many gallons per hour at idle???

Post by roadrunner »

While scan gauge does show fuel used etc I think it would have little bearing on your situation as compared to my truck here in KS. It is nowhere near as cold here as there and idling would use significantly less fuel here due to the engine running richer to compensate for the low temps and also the lower vaporization rate of the fuel there as compared to here. Perhaps one of our more northern "brothers" who has a scan gauge can chime in here. At least the information would be more relevant to your usage.

I did a check on mine and the numbers at 38* ambient temp are as follows:

Cold start idling fast--0.94GPH

Warm engine idling normal-- 0.47GPH

These readings were with all accessories and lights off. As said before in your severe cold your numbers will probably be significantly higher.
2001 CC LS, pewter, stock, 4.3,Wait4meperformance, CFM throttle blade, Helix throttle body spacer, 4spd auto, 3button electric 4x4 shift, heavy duty factory suspension, Bilsteins, 1" rear wheel spacers, skid plates.
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Re: How many gallons per hour at idle???

Post by dualsport »

Hey thanks... That's some good data you posted... I'm sure I'd be sucking more fuel when it's below zero, but now I have a bit of reference. I'm a bit weird I guess, cause I always check my mpg when I fill up :) My wife makes fun of me but I take a bit of comfort in knowing my twin brother does the same thing.

If I'm warming up the pickup for 5-10 minutes each day (morning and before heading home from work) in the dead of winter (-20 to -40 type stuff) and also for my weekend outings as well, then I'm upwards of two hours of idle time each week! Jeepers... that really bites a guy at the pump... But with this data, I'll just run the calc twice- once for the full amount and then again minus two gallons. Kinda makes a guy a little warmer already... :)
2001 Sonoma CC, TB crank, 2" shackles, 2" BL, Helper Springs, 1.25/2.5 Spacers, 31" BFG ATs, Quadbeams, messed up 4wd switch :) miscellaneous squeaks and pings...
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Re: How many gallons per hour at idle???

Post by roadrunner »

Don't feel bad about keeping tabs on your MPG's on every tank. I do as well on all my vehicles. I find it is a good way to head off pending trouble as mileage many times will drop well before any noticeable performance changes are noticed. Especially on a daily driver.
2001 CC LS, pewter, stock, 4.3,Wait4meperformance, CFM throttle blade, Helix throttle body spacer, 4spd auto, 3button electric 4x4 shift, heavy duty factory suspension, Bilsteins, 1" rear wheel spacers, skid plates.
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Re: How many gallons per hour at idle???

Post by killian96ss »

roadrunner wrote:Don't feel bad about keeping tabs on your MPG's on every tank. I do as well on all my vehicles. I find it is a good way to head off pending trouble as mileage many times will drop well before any noticeable performance changes are noticed. Especially on a daily driver.
This is the same reason why I check the mileage on all my vehicles, and is good advice for others to follow. :thumb: You can catch small problems before they become big expensive problems.

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Re: How many gallons per hour at idle???

Post by dualsport »

HJ- what kind of cabin heater do you run? (I did get a chuckle out of the idea of having to chip ice to get into your vehicle ...been there before)

My boss used to manage the pipeline satellite links and they'd run those in all their company rigs- he said they were a no-go when it got seriously cold. I'm not really worried about the cabin temps, just the vehicle temps before stressing it with use (I dress for the outside temps when driving, not the cabin temps :D )


Anybody run that scanguage with the AC/Defrost running? How much fuel draw can I expect? I'm always conscious of only using defrost when I need it in the winter, because it runs the AC system (dries the air... right?). Anyway, just curious.

Thanks guys...

Have a great Thanksgiving!
2001 Sonoma CC, TB crank, 2" shackles, 2" BL, Helper Springs, 1.25/2.5 Spacers, 31" BFG ATs, Quadbeams, messed up 4wd switch :) miscellaneous squeaks and pings...
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Re: How many gallons per hour at idle???

Post by HenryJ »

dualsport wrote:HJ- what kind of cabin heater do you run?
ZeroStart "Little Buddy". There should be a thread on it. I modded mine with a thermostat.

"Speed doesn't kill, suddenly becoming stationary does." - Richard Hammond
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Re: How many gallons per hour at idle???

Post by roadrunner »

Fuel draw with defrost on will depend on speed and usage. I'll try when I get home to give you a value on it at idle. I'm in Vegas right now for Thanksgiving visiting relatives and gettin fat on casino and home-made holiday food.
2001 CC LS, pewter, stock, 4.3,Wait4meperformance, CFM throttle blade, Helix throttle body spacer, 4spd auto, 3button electric 4x4 shift, heavy duty factory suspension, Bilsteins, 1" rear wheel spacers, skid plates.
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Re: How many gallons per hour at idle???

Post by DLP »

I keep a gas record book in the glove box of all the family cars. Nice for reference when things aren't right. I have the SG2 but go by my record book for actual gas milage. Too much hassle clearing it each fillup.

There is a surefire way to test your warmup fuel usage. Fill up at the station. Go inside and buy a magizine and read it in the parking lot for a couple hours. Then fill back up again. If you really want to know!
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Re: How many gallons per hour at idle???

Post by roadrunner »

Sorry go be so slow on the follow up. Waited for colder weather to check the readings. Engine cold idling, defrost on max, outside temp 12*F= 1.26gph. Engine warm same heater settings and same outside temp= 0.50gph.
2001 CC LS, pewter, stock, 4.3,Wait4meperformance, CFM throttle blade, Helix throttle body spacer, 4spd auto, 3button electric 4x4 shift, heavy duty factory suspension, Bilsteins, 1" rear wheel spacers, skid plates.
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Re: How many gallons per hour at idle???

Post by dualsport »

That's some good info to know!

Thanks for gettin back with me... I was checking from time to time, but not gonna pester :)

Well that's interesting... +12 degrees and then normal operating temp. It's hard to say what the draw might be when it's 30 - 40 below and we're warming them up before we drive, but now I have an idea anyway! I've got a few vehicles with the 4.3L and they both get comparable fuel mileage- especially in the winter.

Thanks again!
2001 Sonoma CC, TB crank, 2" shackles, 2" BL, Helper Springs, 1.25/2.5 Spacers, 31" BFG ATs, Quadbeams, messed up 4wd switch :) miscellaneous squeaks and pings...
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Re: How many gallons per hour at idle???

Post by roadrunner »

Yeah there's such a difference in temps from here to where you are I'm sure your fuel draw will be a bit higher. Sounds like you have need of and use for a Scan Gauge II unit in your vehicle. I sure do like mine!!
2001 CC LS, pewter, stock, 4.3,Wait4meperformance, CFM throttle blade, Helix throttle body spacer, 4spd auto, 3button electric 4x4 shift, heavy duty factory suspension, Bilsteins, 1" rear wheel spacers, skid plates.