# 40-50HP and want to save some fuel?



## Glenn9643 (Jan 22, 2006)

If your tractor is 40-50HP have you ever stopped to think about how much unnecessary fuel you often burn to do some PTO related tasks by running at PTO RPM to achieve 540 at the PTO? The power outages this last hurricane season caused me to consider a PTO operated generator, and a 12KW would require about 24PTO HP. Consider how much added fuel would be required to keep the PTO at 2600 for a 50HP tractor than doing the same work at 1750RPM. 

We have about 15 acres that I clip regularly with the bushhog and I've found that if the blades are sharp I can reduce the tractor RPM's from 2600 to about 18-1900 and still get a good cut even with PTO RPM reduced somewhat, resulting in tremendous fuel savings. This is the case if the grass isn't over about 10-12" high. 

I've been looking around for "E-PTO", "Economy PTO" or whatever different models call it, and it's a scarce option.
JD offers it in their 5025 series utility tractors.

Massey Ferguson only offers it in their larger tractors, but not in the 400 series.

McCormick GX CUT's offer it as standard equipment, but their loader capacity for the higher HP CUT's is terrible.

Branson 6530 has it standard but I'm not ready for that yet.

Seems like this would be a great selling point for tractors that have enough power to benefit from it. Anyone else interested?


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## Live Oak (Dec 22, 2003)

It is a great economy option for limited applications but for running a generator, you best bet in my opinion is to have a stand alone diesel or for long term and very occasional use, an LP gas powered standby generator is the most cost effective option in my opinion. They are not cheap but over the long run, if back up power is a recurring issue; the indefinite storage ability of LP is a overwhelming choice. The oil for an LP engine remains clean MUCH longer than a gas or diesel engine as well which is another key maintanence consideration. 

With respect to how much fuel is saved by running the tractor engine at a lower rpm? That can be a mixed bag. Diesel engines are "governed" by the fuel injection pump. In a nutshell, the governing function of the injection pump is to add as much fuel as is neccessary to maintain rpm under load up to its design limit. If the tractor is not run under much of a load, the fuel consumption does not good up as like you would think. Under very heavy loads the fuel consumption can sky rocket. Another consideration is that a generator must be run at a specific rpm to produce 60 hertz power which nearly all appliances run off of; otherwise you can cause damage to electrical appliances that are exposed to under frequency power. A generator that is run at or near max. capacity will place a significant load on the pto depending upon the size of the particular tractor. Most homes require a 20K generator to run pretty much everything as usual which requires a minimum 40 pto hp. You can get by with a smaller generator such as a 15 K which still requires 30 pto hp. but still a continuous moderate to heavy load is place on the pto and hence the engine and I don't think there would be much if any of a fuel savings at a lower rpm under these conditions. This does not even take into account the huge number of hours that can be run up on the tractor if generator use is more than very occasional. During an emergency when you may need your tractor to move downed trees or other uses; running a pto generator will have it tied up as well. 

My John Deere 4410 used approx. 1 gallon per hour regardless of what rpm I run it at unless I am cutting some really heavy vegetation or just idling. With normal running at 2,600 rpm cutting with the 72 inch MMM; I typically get about 10 hours per tank full. If I am cutting really heavy stuff that drags the engine down, I get about 8 hours per tank.


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## OleGrandWizard (Jan 9, 2006)

Very good information there Chief. I had run a few PTO driven implements in the past, especially on my older N and 800 series tractors. I had a old Dearborn saw, a old mill grain grinder, and few smaller items. Of course those ran fine in the 20-30HP at PTO range. I have thought long and hard about adding a nice generator-type system to my home and workshop especially in light of the recent storms. I have heard of PTO-driven generators and thought they were far more cost-effective than you have described. Good information. 

While discussing power issues, I have thought about wind, solar and other options before I complete my rebuild. Any new advancements in energy savings and generation that you know of?


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## Lamar Holland (Dec 28, 2005)

We have a 14,000 gasoline powered genset. Someday, we will upgrade it to a diesel... In the meantime, I must be missing something here, because I use a L 48 TLB, 48 HP Kubota. 7 times each year, I hang the hog mower and go about cutting the fields. I have never had to run at 2600 to retain a clean cut at 540. Our fields are pretty hilly too. So to save diesel fuel, what am I saving? I don't even think about fuel use on my tractor even when using the hoe all day... Most I have ever put in, after non stop use and 8 or so hours,, is 7 gallons. For me it is not worth extra aggravation to try and save 1/10th of a gallon in any given day. This is is what, 27 cents a day saved? I liken this to those fighting over a gas pump at 239, when down the street it is 240. At Cumberland's, 239 regular, is non stop fender benders, shouting arguments and the rest of it... To avoid all this I would go down the street at 240 a gallon. Wife's car only holds 10 gallons to beging with. Not worth the ten cents possible savings, (if getting 10 gallons) to sit there at the other place filling out paperwork over a fender bender...


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## Fordfarm (Dec 27, 2005)

I use a lot of PTO powered equipment with my 8N. Some of it, like my PHD and JD shedder-mower, actually will cut BETTER at lower than 540 RPMs (in some instances). I don't have a proof meter, so I just go "by ear". Listen to your machines, they will tell you what they like/dislike!


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## Chris (Sep 15, 2003)

FF, how does the PHD work with the 8N. I don't have one and I figured that the lack of live PTO would affect the useability and functionality of it? Can you elaborate?


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## Fordfarm (Dec 27, 2005)

It works just like on any other tractor! In fact, it runs it better than my IH 460 or 454 does. I don't "wind it up" just turn it at about 1/4 to 1/2 throttle. When I get done, I just pull the auger up to about 1/2 way out of the hole, idle down to almost nothing, and pull it all the way out and hit the clutch! Then reach down, disengage the PTO and drive to the next one.


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## Glenn9643 (Jan 22, 2006)

I'll just agree to disagree.
We don't need anything more than a 12KW here. In the winter that will power just about everything, as our heat is natural gas but requires the fan to turn by electricity. The 12KW wouldn't need but about half the HP of my tractor at full load.
And as far as fuel consumption not “gooding up” as I would think, I've seen the results time and again clipping the pasture and I know what it'll do for me. I can begin with a topped off fuel tank and clip this place at 2600RPM and will have to refuel when I'm about 2/3 completed. If I reduce the RPM to 18-1900 I'll have ¼ tank left when I finish clipping. It will run the 12KW at about the same load and fuel useage. True, the savings from clipping 15 acres with an economy PTO wouldn't amount to a lot, but over a period of time it adds up and if you were running a generator over a period of several days the difference would mount up pretty quickly. I've about decided to trade up to a cab tractor, but I'm still wanting the E-PTO along with it!


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## Eddinberry (Dec 3, 2006)

I'm wondering about this as well.

My Landini has a 3 speed PTO.
(540, 750,1,000 RPM)

While tilling I often engage at 1,500 Engine RPM with the PTO set at 750RPM, and actual shaft speed is 510-540 RPM.

I see a small but significant fuel consumption drop, over running the Engine at 2,000RPM and the PTO locked in at 540.

Granted the tractor has posted 82hp on the PTO Dyno, and some room to breathe as it were, but under a constant load from an attachment like a PTO generator, it should be easy to figure out what setting and RPM is most economical.

Chief makes some solid points on the fuel pump bumping up the pressure and volume delivered at the injectors under a load, but if there is a surplus of reciprocating inertia that would negate the load, there "Might" be potential savings available.

I reckon it falls under "Your Milage may vary" depending on the tractor, impliment, and work load and folks gotta tinker and take notes.

When I Run the Chopper, I keep the impliment shaft at 540RPM and geared at the 540 setting on account of the varied loads, and use less fuel than gering the PTO up an running lower engine RPMS.

I also gotta consider the wear factor of having internal shafts and gears under a leverage disadvatage.

There's a lot of load going on in that gear box, and I can't afford to have a Tractor go down and wait for repairs during season.

I guess we all gotta find our comfort spot in the matter. 

Stay safe!
Eddinberry


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## bobsacks (Dec 18, 2006)

Down where I am at there are some people who make a Disc Mower to Disc Bine type adapter. It is a two wheeled dolly that holds the mower and you pull it like a bine. Not sure if it would save gas or not but it sure does make it easy. Contact these guys if you want more info - [email protected]


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