Not using all my horses by design??

[Cycledude]

I've recent acquired a good amount of acres, but they're all steep. I have a small tractor, but it's not even close to cutting it on the hills while working (20hp). I need something bigger like an M7060 or L6060 but found a cheap Kubota M108s low profile 8 speed with 1300hrs. Of course, the horse power is way more than I need. Im going to be using a tiller, BH100 backhoe, FEL, and other equipment.

I won't be using all the HP, so I won't been to be hard into pedal. So here's the question. Does it make sense, fuel wise, to get the tractor seeing as I won't be deep into the power band to run and do what I'm looking to do? Particularly with it being 8spd.

I've looked up M7060 and they can easily get to 5+ gph full bore. An M9000 is 5 to 10gph depending on who you ask at full throttle. If this tractor is 10gph at idle it might not be worth it...but I don't know.

(edited for clarity)

108 horsepower wow that is a big jump from your current 20 horsepower. 5-10 GPH sounds high but you definitely can’t believe everything you read. My 55 horsepower LS with a little over 300 hours on it seems to usually use about 1.5 GPH , I have kept records of every fill, sometimes it’s only 1 GPH but it’s usually closer to 1.5 GPH.
So are you planning to get rid of your old tractor and attachments and buy different attachments suitable for a 108 horsepower tractor ?

 

[Atypical_decorum]

108 horsepower wow that is a big jump from your current 20 horsepower. 5-10 GPH sounds high but you definitely can’t believe everything you read. My 55 horsepower LS with a little over 300 hours on it seems to usually use about 1.5 GPH , I have kept records of every fill, sometimes it’s only 1 GPH but it’s usually closer to 1.5 GPH.
So are you planning to get rid of your old tractor and attachments and buy different attachments suitable for a 108 horsepower tractor ?

I would hope not. I found a white paper on other M9000 and another similar sized kubota and the gph was up to 5gph at 75% throttle.

I was hoping the M108s was going to be the same or less at less power required.

Definitely not getting rid of my small tractor or anything I have for it. I can do a lot of smaller jobs with it and I just got new ballasted tires, so there's another 800 reasons to keep it!

The only thing keeping me from that M108s is trying to find a reasonably priced loader. I can't find any La1403's for sale and the new one that fits it is $15k new!

 

[Atypical_decorum]

108 horsepower wow that is a big jump from your current 20 horsepower. 5-10 GPH sounds high but you definitely can’t believe everything you read. My 55 horsepower LS with a little over 300 hours on it seems to usually use about 1.5 GPH , I have kept records of every fill, sometimes it’s only 1 GPH but it’s usually closer to 1.5 GPH.
So are you planning to get rid of your old tractor and attachments and buy different attachments suitable for a 108 horsepower tractor ?

It's a definite jump. But I figure the 50 or 70hp I actually need out of it would be no sweat. As opposed to getting a 50hp constantly at WOT and ocassionaly wishing I had more (ha, like we all do)...

 

[Atypical_decorum]

Sure. We all know the answer. I think you do too.

Since you are looking at a pre emissions model, there is no downside to running a higher hp tractor at a lower rpm. Old style pre emission tractors have flat torque over a wide RPM range, so using a larger pre-emissions diesel at lower rpm will just end up taking a little longer to do the job and burn less fuel in the process.
No real downside for individual use. You can even use lower HP implements that way.

We run our 90 hp pre-emissions tractor at about 1/3 rated rpm when not using the PTO. Since the torque on that engine is flat from idle to full rpm, it becomes a rather heavy 30 hp tractor and uses proportionately less fuel. For PTO use, select a lower gear.

rScotty

I didn't actually know the flatness of the curse. That's good to hear though.

I guess the clarification really lies in if fuel is dumped into the 3.8L engine at a disproportionately high rate to get my lower hp requirements or if there's damage over time to low requirements with the ocassionaly higher need on the fuel pump, valves etc.

Or if it's even a good idea....

Hearing you do the same is good. Have you experienced any down sides??

 

[Atypical_decorum]

I'd be honored. Never had a full sized tractor owner put me on ignore before.

Thank you. Hopefully the good information keeps rolling in.

 

[Atypical_decorum]

Well, not here to sidetrack your post, just going by the incorrect info you provided in your initial post. There was no pre-emission M7060 or M5 Kubota's. Those are new models introduced with emission equipment.

Maybe I read your initial post wrong. You kept mentioning M7060 and M5's.

Not required for the initial question though. Picking up the side piece of information while ignoring the main question and point of the question is akin to trolling. And I sure as you were sitting there writing your response you knew you were on an unrelated tangent but wanted to prove your point.

 

[CobyRupert]

“Theoretically” power is power. The power required is determined by the load, or task, being performed, and the speed/rate it’s being performed at. Not by the tractor being used.

If a task is performed at the same speed/rate, both tractors are providing the same amount of power.

…then you get into the efficiency of the motor at that rate. And at that rpm/torque, etc..
A small wound up turbo engine may be more fuel efficient than a motor operating outside its power band. A heavy tractor may take more fuel to push itself up the hill, etc..

Or vice-versa. Example: a small tractor may use (let’s say) 50% of its energy moving itself and the attachment, and only use 50% on the “task”; whereas a large tractor may only use (say) 20% of its energy on itself and have 80% for the “task”.

Or, if performing the task at different rates, the load’s power requirements may not necessarily be linear with different rates. That is, because of the nature of the load, it may take more than twice the horsepower, or less than twice, to do something at twice the speed.

IMO, there are many, many, variables involved when trying to predict what the fuel-to-task accomplishment ratio will be.
….and don’t forget that “time is money” too.

 

[LittleBittyBigJohn]

I'm going to give anecdotal info since I don't have any lengthy knowledge. I would say go for the big one. I've looked at the same quandary although I have so far used other means to accomplish the projects I was intending for the larger tractor so I ended up not needing the larger machine.

Mechanically you should have no issue. Look at all the hay tractors of different sizes pulling a rake. Power wise my 1025R would probably do, maybe that's extreme but they don't take hardly any power to use. But, lots of people only have a machine or 2 to use and end up with a comically large tractor on a little rake. Lots of people site weight as a reason to go to a larger machine and thus increase HP as a function of what's available in the frame size that offers the weight they are after, think grain carts or plowing.

As far as fuel load I've been using some heavy excavation equipment around my place doing several projects. The dozer and track hoe have a gauge that shows gallons per hour. They are run at constant RPM and depending on load applied go from around .5 gph up to 6-7 gph at that same constant full throttle RPM. My assumption is that you would be using a similar amount of fuel running a smaller one harder or a larger one easier. Probably leaning toward more on the higher HP model closer to no load and more comparatively on the lower HP model on something that is taxing for it and the same load on the higher HP model. That might not have made sense...

 

[Atypical_decorum]

And I have said nothing negative, nor tried to steer you away from emission motored tractors.
I only stated that having a proper sized engine and running it so it keeps it's optimal COMBUSTION (not coolant) temperature up will keep it a lot happier than having a big motor and idling it all the time.
Sorry for any confusion.

Would idling not bring it to propert temperature? What type of running or operating parameters would bring the engine to it's appropriate temperature?

From what ive seen, any engine, diesel or gas, the water pump will eventually circulate the fluid to remove heat from the engine at idle.

 

[Atypical_decorum]

Wow you have issues. Good luck, LOL I only said because you SAID M7060 and because THAT MODEL has a DPF you need to run it hard to avoid problems.
Thought I was just trying to give you some advice, oh well. Go buy a 300 horse tractor and idle it all day for all I care, LOL

Lol. I said I was looking at a possible M7060, too. Stop being a troll please.