How many litres/hr does a 3.2DiD burn at idle?

[dhula]

Whoever guesses the closest wins

537ml/hr

[m_and_m]

And the answer is.......

The answer is 0.75 l/hr
So i reckon you can trust the scan guage

For the scientifically minded:

Test Configuration:
Fuel: Caltex vortex diesel.
Ambient temperature: 18 C
Automatic: in Park
AC : off
All electrics off: headlights, fans, etc.
No fridges, caravans attached.
Engine was warm.

Test Procedure:
1. Went to servo and filled both main and aux tank until to the brim. Car parked slightly downhill to try to prevent air pocket in tank. Also filled up 5l fuel can to use to top-up after test.
2. Drove home 1.2km. Car parked at home on bit more of a down hill. Filled tank up to brim again. Bugga me it took the full 5l can and still needed more!
3. Back to servo to fill up the 5l can again...in wife's car this time.
4. Finished filling tank until it overflowed. Yep, she's now full.
5. Turn off all electrics I could.
6. Started car and stopwatch together.
7. Had dinner. You can omit this step if you want.
Checked on car regularly...easy target for a thief.
8. Waited exactly 1.00 hr and turned off car.
9. Put funnel into tank, and proceeded to add half a metric cup (125ml) of fuel until at a time until the tank overflowed again. Each half cup measure was filled until it overflowed, so each was filled to the brim (125ml)
10. Cleaned the spilt diesel off car and the the driveway

Test Result:
Exactly 6 cup measures. On the last dribble out of the 6th half cup it overflowed. = 750ml

Conclusion:
Surpised me I thought it would have used heaps more.
Recharging an external battery off the car at idle will cause the alternator to put a bit more load on the engine, so it will use slighly more fuel. I think this would be negligible though, as when connecting and disconnecting the external battery to charge it there is no audible change to the engine. Not like the AC turning on and off!
The external battery was only taking in 10amps at idle RPM.

So there you go,
NP diesel uses 750ml of fuel per hour at idle.
NW diesel uses 450ml / hr, according to TC.Barkys' scanguage

[Rovingman]

The answer is 0.75 l/hr
So i reckon you can trust the scan guage

For the scientifically minded:

Test Configuration:
Fuel: caltext vortext diesel.
Ambient temperature: 18 C
Automatic: Park
AC : off
All electrics off: headlights, fans, etc.
No fridges, caravans attached.
Engine was warm.

Test Procedure:
1. Went to servo and filled both main and aux tank until to the brim. Car parked slightly downhill to try to prevent air pocket in tank. Also filled up 5l fuel can to use to top-up after test.
2. Drove home 1.2km. Car parked at home on bit more of a down hill. Filled tank up to brim again. Bugga me it took the full 5l can and still needed more!
3. Back to servo to fill up the 5l can again...in wife's car this time.
4. Finished filling tank until it overflowed. Yep, she's now full.
5. Turn off all electrics I could.
6. Started car and stopwatch together.
7. Had dinner. You can omit this step if you want.
Checked on car regularly...easy target for a thief.
8. Waited exactly 1.00 hr and turned off car.
9. Put funnel into tank, and proceeded to add half a metric cup (125ml) of fuel until at a time until the tank overflowed again. Each half cup measure was filled until it overflowed, so each was filled to the brim (125ml)
10. Cleaned the spilt diesel off car and the the driveway

Test Result:
Exactly 6 cup measures. On the last dribble out of the 6th half cup it overflowed. = 750ml

Conclusion:
Surpised me I thought it would have used heaps more.
Recharging an external battery off the car at idle will cause the alternator to put a bit more load on the engine, so it will use slighly more fuel. I think this would be negligible though, as when connecting and disconnecting the external battery to charge it there is no audible change to the engine. Not like the AC turning on and off!
The external battery was only taking in 10amps at idle RPM.

So there you go,
NP diesel uses 750ml of fuel per hour at idle.
NW diesel uses 450ml / hr, according to TC.Barkys' scanguage

Classic

[Goodsy]

So there you go,
NP diesel uses 750ml of fuel per hour at idle.
NW diesel uses 450ml / hr, according to TC.Barkys' scanguage

I call BS.

[m_and_m]

I call BS.

By BS i presume you mean Big Surprise

[Goodsy]

Um. Yep.

[erad]

The next question to be answered is "How many amps can the alternator put out when the engine is at idle speed?" This is the real question - can I charge a battery (economically) by using the $55000 battery charger instead of a small, dedicated genset?

[Goodsy]

The next question to be answered is "How many amps can the alternator put out when the engine is at idle speed?" This is the real question - can I charge a battery (economically) by using the $55000 battery charger instead of a small, dedicated genset?

No.

[m_and_m]

The next question to be answered is "How many amps can the alternator put out when the engine is at idle speed?" This is the real question - can I charge a battery (economically) by using the $55000 battery charger instead of a small, dedicated genset?

Great question.
BTW, $55k...ripped off. Mine cost heaps less

Based on a few seconds of research on this great forum came up with the following:

NP model had a 110 amp in the 3.8 ltr and 125 amp in the 3.2 DID model .
NS had a 120 amp across the range.
NT/NW 120 amp.

For continuous operation I'd keep the alt at 70% max rating.
So, using a 120A alt, save 20A? for running the car electrics = 70A max usable surplus charge.
70A=~ 13V x 70A = 900W. At continuous max. output.

This would be at higher than idle RPM of course.

Next is to concoct a test rig that can increase the load on the alterator to work out it's usable max at idle RPM.

[old Jack]

I did some tong test on my PB and was surprised that it needed 36amps just to run the engine! Results in this link;

http://www2.pajeroclub.com.au/forum/showpost.php?p=329863&postcount=8

cheers, old Jack.

[m_and_m]

Gotta love Easter. Able to do stuff you' rarely have time to.

Here's the results of my experiment.

Objective 1: How many Amps I can draw from the alternator while idling to charge a battery.

Objective 2: Can I use my DiD as a economical generator..or should I get a portable Honda/Yamaha?

Test Configuration:
600w modified sine wave inverter connected across starter battery
Power meter connected to 240V output of inverter
Heat gun connected to power meter as variable load. (I can adjust the heater via dial)
Connect voltmeter across starter battery.

Conducted test with engine off, and also at idle (800 RPM).
engine was cold, So idle RPM a bit higher than normal.

Test Procedure:
1. See what the setup does off 240v mains
1.1 Put heat gun on lowest heat setting and turn on. (250W)
1.2 Adjust the heat gun's heater control to various settings between min and max. Result was 230 to 1450 watts. Good, I can vary the load appropriately.
2. Connect setup to the 12v to 240v inverter running off battery.
3. Turn on 240v inverter
Repeat below for engine off, then engine on idle:

4. Put heat gun on lowest heat setting and turn on.
5. Adjust the 240v heat gun's heater control to various settings up to inverters max of 600w
6. Record voltage and output power; current was calculated.

Test Results:
Raw test results are here

Conclusions:
Objective 1
Voltage across battery was 13.5@40A, so capable of providing even more, and this didn't compensate for the ~10% loss due to the inverter.
So, I can conclude the alternator will supply more than 50amps to an external load when engine is just idling.
This is more than enough to charge an external battery.

Objective 2:
Whether or not it can replace an external honda/yamaha generator is inconclusive. i need a better way to load up the alternator. My 600w didn't push the alternator it to the limit.

[Goodsy]

Does the engine consume more fuel to keep idle rpm correct with alternator load??

[m_and_m]

Does the engine consume more fuel to keep idle rpm correct with alternator load??

Based on TC.Barky's results I expect so, but haven't measured mine yet

[erad]

Does the engine consume more fuel to keep idle rpm correct with alternator load??

I would say that the engine must increase revs to compensate for the extra load. At idle, the engine is producing enough power to keep it going and that is all. If you load say 10 amps &14 v = 140 watts, it has to produce 140 watts more to keep running. The engine speed must increase, although not by much. If you want to try this out, have the engine running and then turn on a heavy load eg high beam headlights, or airconditioning. The engine speeds up slightly. For A/C the speed is supposed to increase from 700 R/min to up to 1000 for a manual transmission, although a lot of that extra power would be in the compressor itself. Hi beam headlights will load up the alternator a bit but I doubt that you will see much increase in speed.

[m_and_m]

With my car, the RPMs stay the same when AC activates etc.
Suggest it just burns more fuel to maintain the same RPM.