Any guesses on Gal/Hr for 3520-3720 and the 4000 20's?

[AKfish]

I read a post on the JD Buying forum and a current 990 owner finished mowing 20 acres and figured he'd only burned about 4 gallons of fuel (1/3 of a tank).

Got me to wonder how much fuel the owner's of 3520-3720 and the larger 4000 series of JD CUT's figure they burn for every hour on the meter.

Any "seat of the tractor" ideas on how well your tractor is on fuel consumption?

Thanks for any and all info--

AKfish

 

[TheBigKahuna]

Funny you should ask. I just made a note of my hours/gallon. I have a 3520 with cab. While mowing I get just over 1 hour/gallon. I have 50 hours on my tractor.

Glenn.

 

[nmu98]

I have a 3720 without a cab, and doing some heavy loader work, I went through just over a gallon per hour. I was stripping a section of black dirt, and I went through just over 10 gallons on 8.25 hours. The dirt was loose so there was a lot of pushing and lifting.....

I dont have the hours on the 4720 yet to let you know the difference.... But it seems to like fuel a bit more..... Im still on the first tank, and thats judging by the fuel guage..... Not very accurate..

 

[Greyfields]

JD 3520
Fuel System
Type Direct injection
Injection Pump Type In-line with electric shutoff
U.S. gal./hr (L/hr) @ 100% load* 2.4 (9.1)
*Fuel consumption rate should be used for comparison purposes only. ---

JD 3720
Fuel System
Type Direct injection
Injection Pump Type In-line with electric shutoff
U.S. gal./hr (L/hr) @ 100% load* 2.8 (10.6)
*Fuel consumption rate should be used for comparison purposes only. ---

JD 4120
Fuel System
Type Direct injection
Injection Pump Type In-line with electric shutoff
U.S. gal./hr (L/hr) @ 100% load* 2.46 (9.3)
*Fuel consumption rate should be used for comparison purposes only. ---

JD 4720
Fuel System
Type Direct Injection
Injection Pump Type In-line with electric shutoff
U.S. gal./hr (L/hr) @ 100% load* 3.28 (12.4)
*Fuel consumption rate should be used for comparison purposes only. ---

 

[AKfish]

Sounds like the 35-3720 sips fuel. Even the turbo "Yammy's"!

The JD power-tech might be a bit hungrier...

I can appreciate the "posted specs" from the manufacturer but that's like only considering the EPA estimates on new cars and trucks. And the 3720 is real close to the 4120.
But, it's only a "ballpark" estimate and there's alot of variability depending upon how, where you use your vehicle or tractor.

If I'm tedding hay with my JD 970 @ 2,200 rpm (6th gear), I think I'm only burning about .75gal/hr.

But, if I'm pulling the tiller thru broken sod @ 2,600 rpm (1st-2nd gear), I'd guess that I'm burning over a gallon/hr --- likely, 1.25gal/hr.

Interested to hear from owner's of the turbo-3000 series and the 4000 series how they do on fuel and how much it might change depending upon what kind of work they're doin'.

Can hardly wait to hear how Greyfield's 4120 does with that new baler...

AKfish

 

[nmu98]

I would like to see the numbers at 50 and 75% load. That seems to be more where they are run. There might be more of a gap there.

 

[Greyfields]

Can hardly wait to hear how Greyfield's 4120 does with that new baler...
AKfish

Disc mower, raker/tedder and seed drill will be here tomorrow. Baler on Monday morning..... I'm dying here with excitement.

The 4120 certainly uses more fuel mowing, since it's cranked up to 2400 RPM. I can mow for around 6 hours until having to stop and refuel. So the ~2.5 gal/hour seems darn close. Of course pottering around with the front loader in the yard, I doubt I'm coming anywhere close to that.

 

[Z-Michigan]

Nebraska Tractor Test Lab has numbers on the 4320 and all larger models at:

TTL test reports/JD Deere

In my experience with my 5105, I use far less than the tests indicate, even when doing heavy work like plowing or discing. I am averaging something like 0.8 gal/hour and I feel like I'm using the tractor pretty hard. Time idling will dramatically reduce the consumption indicated based on your hourmeter, but I still was impressed at how little fuel I used for several hours of hard plowing in 4wd. Unless you are working on more than 10 acres at a time, or doing some painfully slow task like rototilling, I think you will find consumption is 1 gal/hr or less (based on meter hours) for any of the models you're looking at.

 

[RalphVa]

I'd think fuel consumption ought to directly prorate with hp on a tractor. Mine has been 0.46 gallons/hr over 250 hours of operation on my 18.5 hp 4010. There was a posting on these elsewhere a while back.

Fuel consumption on cars usually prorates by weight. On carburetor cars, it was 30 mpg-ton, with diesels at 45 mpg-ton. This was back in the 80s. With fuel injection, the gas cars figure is up to about 40 mpg-ton. Newer diesels now are up to around 60 mpg-ton.

Ralph

 

[jcmseven]

Both my 3720's burned about 1.25--1.50 gallons per hour when mowing at PTO speed. They both have been MORE fuel efficient than my NON turbo 4310 before them. The 4520 I had burned about 2 gallons per hour in similar circumstances, but it could pull a six OR seven foot mower no problem, where my 3720 could pull a seven foot, but for tractor size felt more comfy with the six footer. So the big thing to keep in mind, especially with heavy duty PTO work, is that the Powertech engines are definitely more thirsty, but the machines they are powering are larger and can get bigger jobs done somewhat quicker,so the actual fuel used per work done is probably about the same.

John M

 

[tuolumne]

I can offer a guess at 50% - 75% load...my 3520 has 46 hours on the meter and I've put 15 gallons into it. The gauge currently reads a little over 3/4 full, so call that 18 total gallons. That is .4 gallons/hour. To guess at what those hours were...
- 10 hours on the backhoe at 2000 rpm
- 13 hours doing loader work or moving logs at 1500 rpm (I leave the throttle set around there and use the foot throttle occasionally for a little more oomph)
- 3 hours?? idle time while thinking, greasing, switching implements etc.
-20 hours using the chipper at 2500 rpm (avg. I was running it at about 2300 for a while when new, and now run it at 2600)
This is a relatively small displacement engine, and just sips fuel. Occasionally I'll hear the turbo whine when a large log goes through the chipper, or when climbing the steep hills on our property. It is nice to know I can get a full days work out of a five gallon gas can. The 2.7 gph listed at PTO RPMs sounds a bit high to me.

 

[nmu98]

I can offer a guess at 50% - 75% load...my 3520 has 46 hours on the meter and I've put 15 gallons into it. The gauge currently reads a little over 3/4 full, so call that 18 total gallons. That is .4 gallons/hour. To guess at what those hours were...
- 10 hours on the backhoe at 2000 rpm
- 13 hours doing loader work or moving logs at 1500 rpm (I leave the throttle set around there and use the foot throttle occasionally for a little more oomph)
- 3 hours?? idle time while thinking, greasing, switching implements etc.
-20 hours using the chipper at 2500 rpm (avg. I was running it at about 2300 for a while when new, and now run it at 2600)
This is a relatively small displacement engine, and just sips fuel. Occasionally I'll hear the turbo whine when a large log goes through the chipper, or when climbing the steep hills on our property. It is nice to know I can get a full days work out of a five gallon gas can. The 2.7 gph listed at PTO RPMs sounds a bit high to me.

I dont think your using the tracktor ar 50 to 75% load... Your usiung it at 50 to 75% of full operating throttle.... You can run your rpms at full throttle and have very little load on the engine... Load is the amount of "work" the engine is doing.

BTW, I have put as much fuel in my 3720 in the last 25 hours as you have in the time you have owned it...... Your doing well...

 

[tuolumne]

You're correct, the engine has not been under significant load during all of these hours. I am sure that a task like heavy mowing would be using more fuel.

 

[Z-Michigan]

I'd think fuel consumption ought to directly prorate with hp on a tractor.

There are actually very large differences between tractors in terms of the fuel used per hp-hour. The NE tractor tests provide this figure. Very efficient tractors may burn .4 lb per hp/hr while many common but less efficient models burn .5 to .55, and some go over .6. All this is for rated RPM and rated hp; the test results I've seen show that max power is typically a fraction more efficient than rated rpm (maybe by 1-2%) and lower power levels are usually dramatically less efficient.

The good news for JD owners is that from reading bunches of the NE tractor test reports, JDs are often among the best in fuel efficiency, sometimes by a large margin. Fewer cylinders and larger displacement usually go along with better efficiency. Turbo or non-turbo doesn't seem to correlate either good or bad.

 

[AKfish]

Z- thanks for the link to the Nebraska testing site. Great info! (Did note that your 5105 is just slightly more efficient than the 4320...)

Nonetheless, maybe you can shed some light on the tables --- I just could not understand the "Varying Power and Fuel Consumption" table for the life of me!!

It listed the Max Hp and Operating RPM at the top of the table example; 4320 = 41.58hp @ 2399 RPM and then it went all the way down to 0.85hp @ 2649 RPM.

That is just bass ackwards to my pea brain! I realize that at some level of RPM's the HP begins to plateau and actually drops off --- but not to the extent that the table illustrates!

Don't get it ---

Thanks again.

AKfish

 

[Z-Michigan]

I believe that the varying power chart represents fuel consumption at the engine's "high idle" where you are running high rpm's under moderate to almost no load. I'm not sure I find it very useful, but that's what it is. Most of us of course will be running much lower rpm's at lower load, or at the most will be running the rated speed for 540 PTO rpm.

I chose my 5105 in part because of the efficiency indicated in their tests. Based on my experience and reading other people's fuel use here and on the NH forums, I think the test is a good guide.