Horsepower hours per gallon- help me understand

[RalphVa]

My JD 4010 with 18.5 hp diesel used 0.46 gph over 660 hours of varied operations. My new JD 1025 with 39 hours is using pretty much a hp proration (24.2/18.5) of the 4010's usage after some initial high usages, probably because the engine was still tight.

Gasoline engines with carburetors will use 50% more than the above based on data a bunch of us engineers took on our own autos back in the 70s. A turbo engine will use probably 25 or so less. Fuel injection (gasoline) will reduce comsumption another probably 25%. Injected turbo gas engines have near the same fuel usage or less than a non turbo diesel. A turbo diesel will beat them all.

Ralph

 

[Kaliburz]

I may have replied to this before already....but I may have forgot

The re-powered grape harvester using a Ford 4630 engine (originally a Ford 3000) seems to be able to run 10-12 hours before either we run out (fuel gauge doesn't work) or refuel it. Before the tach went out (gonna replace it w/ a Tiny Tac), we would be running the engine about 1400-1600 rpms- as the PTO runs a big hydraulic pump. Once it's started, it doesn't get shut off till we end for the day. I'm planning on mounting a bigger fuel tank on it and using an electric pump to bring the fuel up to the engine. I always did find it odd that the OEM set up just used gravity to get the fuel to the engine. Based on this, I can say that in hour use, it's about a gallon of diesel an hour or just under ($3.50 a hour for off road fuel).

The two JD tractors that the harvester loads into (2640 and 2030) seem to last at least two days. That's 8-12hr shift. Granted, they are not full power loads....just pulling a grape gondola at 1200 rpms or so. The gondolas can carry 4/4.5 tons each- trailer weighs 1500lbs empty. In reality, only one loads at a time, so it really runs half the time (unless driver keeps in on). It has a 19 gallon fuel tank....and we've never ran it out of fuel (one gauge doesn't work, other is iffy). I'm guessing we are refueling at 3/4 empty, but it could be just past half.... So, if I had guess, it's probably using 1/2 gallon or so of fuel per hour on average; less if they shut off between loadings (assuming fueling at 3/4 empty) and two days working (8-10 hr shifts sometimes 12).

Oh, the 2030 was repowered w/ a 80HP engine (new) in 1993....it actually uses less fuel then the 2640 if both are in the field at the same time doing the same "work" (ie disking the field).

So I can say, for grape harvesting, the 3 diesels we run, it's about 2 gallons per hour total....at current prices, between $7-8.00 per hour.


But, the way tractors are rated can be hard to figure out how much fuel it uses per hour. It's not like on road vehicles and miles per gallon, two numbers to figure out. When the "load" is factored in to tractor equations, most owners have NO idea what the load is vs the test conditions that were used to get the number.

So the best someone could do is look look at the hour meter and fill the tank full. Use their tractor and use their tractor. When they fill it, make note how many hours it ran and how many gallons it took to fill the tank. Back to a two number calculation..... is it accurate. Well, for your tractor yes, for someone else's tractor no. Same model tractor running for 1 hour doing totally different things will have two different fuel consumptions (ie loader work vs rototiller).

 

[SPYDERLK]

Our BX1500, due to the HST, can be easily operated at constant full power while snow throwing. The engine at nominal 15hp [net] output is using very close to 1GPH. So 15hphr per gallon or .066G per hphr.
larry

 

[Jerry/MT]

Our BX1500, due to the HST, can be easily operated at constant full power while snow throwing. The engine at nominal 15hp [net] output is using very close to 1GPH. So 15hphr per gallon or .066G per hphr.
larry

I'm more familiar with the BSFC in lbs/hp-hr (old airplane guy) and your BSFC number is around 0.45 lb/hp-hr which sounds like a realistic ball park figure for the engine you have.

 

[SPYDERLK]

I'm more familiar with the BSFC in lbs/hp-hr (old airplane guy) and your BSFC number is around 0.45 lb/hp-hr which sounds like a realistic ball park figure for the engine you have.

Thx for the cross check! ... Id like to do a more meticulous check on use rate but the Kubota thrower is messed up with a bent impeller. ... A rather fragile unit considering the price. Not easy to fix, but Ill get to it eventually. :confused3:
larry

 

[Jerry/MT]

Thx for the cross check! ... Id like to do a more meticulous check on use rate but the Kubota thrower is messed up with a bent impeller. ... A rather fragile unit considering the price. Not easy to fix, but Ill get to it eventually. :confused3:
larry

Getting accurate specific fuel consumption data a really difficult to do without a bunch of eleborate intrumentation (fuel flow meters, dyno, etc) and excellent experimental techniques (fuel LHV determination, etc) and is beyond most tractor users capability. The Nebraska tests offer the best numbers.The OEM's probaby have some of this data available and it would be nice if they published it in the the owner's manual but if they did the first time someone used more gallons per hour than the published values their phone would be ringing off the hook.

Fuel usage, like car fuel mileage, is so senstive to actual use conditions that the user "measured numbers" would be all over the place. But I wish they would publish the BSFC, HP, and torque vs rpm curves anyway! It would help people get an idea where min BSFC was and they could use that as a guide for where they should operate for min fuel burn. However you still have to match the HP requirements of what implement you are using and that will not always be at min fuel burn.

 

[Industrial Toys]

^^^Now throw in things like fuel variations, altitude and temperature.

When a particularly inefficient tractor like out JD6200 wastes fuel, where does it actually go? It has a turbo and yet is still a pig!

 

[Jerry/MT]

^^^Now throw in things like fuel variations, altitude and temperature.

When a particularly inefficient tractor like out JD6200 wastes fuel, where does it actually go? It has a turbo and yet is still a pig!

The loss shows up as heat; heat in the tractor gear fluids/hydraulics, heat rejected from the radiator, heat out the exhaust, heat in the lube oil, heat from the block, etc. The engine itself is pretty efficient but gear train losses, wheel slippage, etc reduce power delivered th the pto and wheels.

Why do you say the JD6200 is particularly "inefficient"?

 

[Industrial Toys]

The dealer just happened to "confess" that to me after I had bought the tractor. But that was when fuel was still CHEAP, so no big deal. I always suspected that the tractor was not great on fuel. I just installed a meter and electic fuel pump on my farm supply and am horrified just how bad it is! I know, sometimes you can forget all the work you did on one tank of fuel, but it seems to me that I burned thirty something litres just blowing my 1000 foot laneway a couple of times! Don't quote me on that, as I will have to watch it closer, but I almost don't want to know! lol

What should be more wastfull is my Hydro Kubota R510 wheel loader and yet that thing is wonderfully stingy on fuel.

 

[Diamondpilot]

Chris

What load did you have on the pto when you measured the fuel flow. If you measured the fuel flow when it was on the dyno, you'd have an idea what the bsfc of the system through to the pto shaft was. In general, bsfc would be higher than if you measured the gross power at the engine shaft because of the gear train losses.The level you qouted is much lower than the typical tractor levels measures at the Tractor Test Lab and you have a very small engine. Scaling laws say you tractor shoud be worse not better.

Never measured it on the dyno. I just know I can bush hog for 8 hours, snow plow about the same, ect on a tank of fuel.

Chris