Idling mpg
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T4runner13
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Just curious but why would one let it idle through a tank of gas?
BlackWorksInc
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The only reason I would think of is if you had a power inverter or something and needed constant power for a while. I had thought about installing a high output alternator to accomodate possible external voltage supplies.
This is exactly what I had in mind.
JB.
New member
I've gathered longer display data on a few other occasions like in the linked thread and, based on that, I'm comfortable with the rule of thumb of 2.5hrs of idle per gallon, especially with it being so close to greasefingers ProScan calculations on page 2 of that thread.
If you get the scan guage data, please report back.
If you get the scan guage data, please report back.
Not wanting to flame, just want to get that out of the way. (it's going to sound like it.... I even manage to mention an Xterra in there.. )
During a recent trip, my buddy left his xterra with his two horse-like pups with the A/C running on high for ~2hours. We were BSing in the driveway and it was too hot to let them run around outside. He managed to take a 1/4 of a tank chunk (his is an 09..~18ish gallons). We noticed it when we gassed up to leave town.
Based on your calcs, the A/C either did it in, or the Xterra just drinks fuel regardless of what it happens to be doing. (both/either/neither could be true)
Normally on trips we do about the same distance on the same fuel, so unless his idle drinks 2-3 times as much fuel as our 4runners I am not sure that makes sense.
I totally agree it would be nice to know how long it will run at idle with a full tank. I have a 1600Watt Inverter that in the event of an emergency would need to be able to run a few emergency appliances. Be nice to know if that is 4 hours or 12 hours.. (I know he has to carry extra gas because of the pups after we figured this out...)
JB.
New member
Seems like a good place for a quick, estimation comparison.
Imagine a perfectly flat road on a windless day. Under those conditions a 4runner could cruise at 30mph in 5th gear. I don't think assuming 30mpg in that scenario is a stretch. So in that scenario, the 4Runner gets 1 hour per gallon (1hpg) while driving down the road. Intuitively, it doesn't seem unreasonable to double that figure for pure idling. Compare those figures to your friend's scenario which, on the surface, was getting him .44hpg, which is not much better than the .33hpg produced if you change the above scenario to 60mph and 20mpg.
As another data point, I idled once for 10hrs (link earlier) starting with the needle below one half and didn't come close to running the tank dry.
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All good info. I had a few times this last weekend to let the T4R idle for 30-60 minutes at a time to charge up the aux battery. It seems like even with the A/C on full blast I didn't notice any noticeable fuel consumption on the guage...(I was in Death Valley).
I'll have to do more testing on it. Being in SoCal, it is more likely that I would idle with the A/C on than the heater. And I am sure the A/C does add some drag on the engine and consumer more fuel. But like others have posted, I'd bet it would be many many hours....
I'll have to do more testing on it. Being in SoCal, it is more likely that I would idle with the A/C on than the heater. And I am sure the A/C does add some drag on the engine and consumer more fuel. But like others have posted, I'd bet it would be many many hours....
JB.
New member
My only concern about long idling is for the CATS. I've idled for 1-4 hours many times but will only do it in cold weather. The warmer it is, the shorter the idling time. In the kind of heat we've been having lately, I don't like letting it go more than 10 minutes, but that's probably conservative. The owners manual sets a limit of 20 minutes (in context of the CATS).
Here's a thread that's a good read.
http://www.toyota-4runner.org/4th-gen-t4rs/61631-catalitic-converter-lifespan.html
Here's a thread that's a good read.
http://www.toyota-4runner.org/4th-gen-t4rs/61631-catalitic-converter-lifespan.html
jaybird93000
New member
in response to the Xterra question, my first truck was an 06 Frontier, which has the same engine as the Xterra. Those engines idle at a higher rpm than ours, by around 800 if i remember correctly, which would increase gas consumption when it's not in gear right? Just a thought.
Acidmeld
New member
Not necessarily. The ecu can adjust timing to idle higher on less fuel. For example, when in park or neutral, the 1gr motor in our t4r will rev to without using more fuel per rev.
