idling fuel consumption - DT360

[icnivad]

I have a DT 360 and was curious how much fuel I might consume while idling. Does anyone have any stats on this? I was considering adding a couple more alternators and using my engine as a ~4kw generator at Burning Man. The other consideration is would it be damaging to the engine to run it at low rpms for so long?

 

[Crazy]

I bet you will burn 1/3 to 1/2 gallon per hour. That is just a guess. Not an educated guess, just a guess.

 

[PossumLiving]

I would use a cheap 2-cyle generator and a 40-amp battery charger before I would idle the main engine to generate electricity.
The engine won't oil itself very well while idling. It also might develop hot spots from insufficient coolant flow. The engine can set up damaging resonant vibrations, too. Believe it or not, engines have been known to break the crankshaft due to extended idling. At the very least you would need to run it at a fast idle, and maybe even incorporate an electronic controller to periodically raise the engine speed for a second or two.
Lastly, automotive alternators are horribly inefficient, and running more than one of them compounds the problem.

 

[Crazy]

I would use a cheap 2-cyle generator and a 40-amp battery charger before I would idle the main engine to generate electricity.
The engine won't oil itself very well while idling. It also might develop hot spots from insufficient coolant flow. The engine can set up damaging resonant vibrations, too. Believe it or not, engines have been known to break the crankshaft due to extended idling. At the very least you would need to run it at a fast idle, and maybe even incorporate an electronic controller to periodically raise the engine speed for a second or two.
Lastly, automotive alternators are horribly inefficient, and running more than one of them compounds the problem.

Yeah, what he said too.

 

[kimberlink-SKO]

I would use a cheap 2-cyle generator and a 40-amp battery charger before I would idle the main engine to generate electricity.
The engine won't oil itself very well while idling. It also might develop hot spots from insufficient coolant flow. The engine can set up damaging resonant vibrations, too. Believe it or not, engines have been known to break the crankshaft due to extended idling. At the very least you would need to run it at a fast idle, and maybe even incorporate an electronic controller to periodically raise the engine speed for a second or two.
Lastly, automotive alternators are horribly inefficient, and running more than one of them compounds the problem.

Ditto; or a 4 cycle genny, couple hundred bucks at most home improvement stores, plus the Big Rigs average 1-2 gph while idling (according to Modern Marvels ) so I'd guess 1/2-1 gph.

 

[travelinwithus]

I have been looking into this as well. I found a paper a student was doing on bus emissions for his degree of master science. You can view it here: http://users.rowan.edu/~marchese/hearne041004.pdf (fuel consumption info on page 101.) He tested I believe three different school buses and one had a DT-466. In the paper he reported that the DT motor burned a little less than .4 gallons per hour. He did not state if this was at idle or an increased idle so I assume it was idling at the factory idle specification. As far as idle I have had people tell me and read that if you idle for extended periods of time you need to idle it up between 800 and 1000 rpms to increase the oil pressure. Hope this helps cause it was difficult for me to find the same info when I was looking.

 

[kimberlink-SKO]

so using the .4 gph for idle times 24 hours in a day thats 9.6 gallons per day at 4 bucks a gallon thats 38.40 dollars time however many days. lets say 10 days which equals 384.oo dollars. For about 350.00 you can get a portable 3.5-4 KW gas or propane generator and save the bus engine for getting home...

Just my two cents for whats its worth. not intended to upset anyone so please dont let it. just wanted to point this out.

 

[Crazy]

As far as idle I have had people tell me and read that if you idle for extended periods of time you need to idle it up between 800 and 1000 rpms to increase the oil pressure. Hope this helps cause it was difficult for me to find the same info when I was looking.

This makes sense because my bus vibrates a lot when sitting at idle. If I bump the rpms by just 100 rpm, the engine is much smoother.

 

[PossumLiving]

Keep in mind that the .4 gph figure said nothing about powering a load with it. If you draw current from the alternator, that will show up as increased fuel usage over just idling with no load. Let's say for example that you use 50 amperes continuous at 14.2 volts. That is 710 watts, but because the alternator is no more than 50% efficient (I have tested this, btw) the actual power used would be over 1400 watts. So the actual fuel usage would be .4 gph (assuming that is an accurate figure) PLUS however much fuel it takes to generate 1400 watts, which for a really efficient diesel engine would be about .15 to .2 gph. Still not much increase, but it gets worse as you draw more current. It wouldn't take long for the fuel savings to pay for a generator. Most of the small generators use a quart per hour or less, under average loads. Small diesel gensets are even better.

 

[opus-SKO]

Nah, I wouldnt want to put the hours on the big engine or idle my engine at one rpm too long.

You can find a Champion 3500W for about $230 if you look hard. They are a great Chinese knockoff generator. I spent a LOT of time researching them and found a lot of positive. Even if you run it for 2 yrs and junk it, pretty cheap to replace.

 

[travelinwithus]

Yep, I agree with all of the above. When I was researching it I never intended on running 24 hours a day. I was looking at running electric heaters in the bus which would need constant input from the alternator in order to run all night. After my research and discovering the costs, i.e. fuel and possible engine damabe, I opted for a propane heater . We won't be using a ton of electricity so I am also looking into solar panels for recharging rather than a genny.

 

[opus-SKO]

If you arent going to use a ton of electricity, why spend the money, time fuss and the ugliness of solar? Just get a small generator and keep it simple.

 

[Motobus]

Nah, I wouldnt want to put the hours on the big engine or idle my engine at one rpm too long.

You can find a Champion 3500W for about $230 if you look hard. They are a great Chinese knockoff generator. I spent a LOT of time researching them and found a lot of positive. Even if you run it for 2 yrs and junk it, pretty cheap to replace.

I have had one for three years I think. Starts right up every time and runs like a champ. I got mine for $295 at TSC.

 

[travelinwithus]

If you arent going to use a ton of electricity, why spend the money, time fuss and the ugliness of solar? Just get a small generator and keep it simple.

When I say I won't use a ton, I mean I would be able to keep up with a 45 watt set of panels. So I could spend money once on a set of panels and not pay again or I could spend a couple hundred dollars on a genny and continue paying as long as I use it. That is my thought process at this moment. I haven't decided one way or another.

 

[PossumLiving]

...opted for a propane heater . We won't be using a ton of electricity so I am also looking into solar panels for recharging rather than a genny.

That makes perfect sense. The 45 watt panels should be good for about 12-15 ampere-hours of recharging capability per day. Not a huge amount, but enough for judicious use of a couple of lights and maybe a stereo or TV. If necessary, you could start and fast-idle the main engine for maybe 30 minutes every other day to take up the slack.