Tractor Sizing How much HP do I really need?

[k0ua]

I have never ever pressed on the hydrostat pedal with any of the three hydro tractors I have owned, in LO range and not had the wheels turn. I don't think the designers would make one that wouldn't do that. Maybe it is possible, but it would be a function of where the relief pressure on the HST was set too low so that sufficient pressure could not be developed in the HST pump to cause the wheels to spin. And this would not be a problem with horsepower normally, but how the relief valve is set.

A 25 horsepower engine should be able to "grenade" the pump of any HST tractor if the relief valve was set high enough and the load on the pump was enough. Say the wheels were chained down to the ground and cannot turn, and the relief valve is totally bypassed, and you apply 25 horsepower to the pump, something is going to give. Shaft, pump housing, something is going to go boom

So I don't believe your scenario of pressing the "go" pedal and the tractor not moving from lack of horsepower is going to happen. 25 horsepower or 250 horsepower.

 

[jenkinsph]

My mower has about the same pto hp. as the Mahindra you are considering and works well with my small chipper. I have a DR 3pt chipper with a 3" capacity and no problems running branches of this size. I think you should be fine for post holes 12" and below if you don't over load it.

It should be able to pull well with the 3 range hydro if well ballasted, just don't overload a trailer. Better to make more trips on a small property.

Overall this tractor looks like a good choice for your intended uses imo.

 

[IndyIan]

The only time I wish I had more hp is doing silly things like running a 5x4 round baler.

 

[arrow]

I'm fine with moving slowly as long as I'm moving. This tractor weighs 2459 lbs, Fill the tires, add wheel weights and a well fed driver should be over 3,000 Lbs. To me hypothetically if I chained the tractor to an unmovable object, on dry pavement in low range, 4WD engaged, rear axle locked when you press the HST pedal, the tires should spin. If they don't than the traction exceeds the power (Torque specifically) and more power could be useful. If the tires do spin more HP would not help at all.

To add fuel to the fire: I have this tractor only it's called the 3016. I test drove this tractor with hst and didn't like it much. Felt it too underpowered for HST with this amount of hp. (Old Pilgrim might have something to say about this as he loves his 3016 HST). I use this tractor hard and have pics all over this forum of it doing inordinate work for it's size. Plus this was about the last geared tractor the dealer had on his lot and I got it for a song.

I now sit on 5 acres of land but used to have 110 just behind the house. This tractor traveled on at least 20 acres skidding good size logs in for the chainsaw kill without so much as a hiccup. It could easily tow in a 3000# hitch of logs and then stack these stems no matter what the thickness and on the pic of the logging truck, you can see what it brought up going up a 30% incline. I agree with Island Tractor this time about the old axiom: "you never can have a tractor too big or with less hp". As a generality this may hold some water but the reality is a tractor must be relegated to what it's purpose is combined with the "wiring" or makeup of the purchaser. It takes me 12 days of 3-5 hr per day time slots to gather just about six cords of wood from standing tree to split and stacked on a yearly basis. I probably could knock off 3 days of that time with a larger tractor but 12 days is plenty fast enough for me. This tractor fits my needs and makeup to a tee.

When I'm done with wood, I would strongly consider trading this tractor in for a max 28 or whatever the designation is today for this size. To me, that would be a righteous machine with a mower, front end loader and snow blower to do just about any work I desired except fill a logging truck with those size logs. (then again I'm supposed to be done with wood at some point in favor of a nuclear powered furnace about the size of a printer).

 

[4570Man]

I have never ever pressed on the hydrostat pedal with any of the three hydro tractors I have owned, in LO range and not had the wheels turn. I don't think the designers would make one that wouldn't do that. Maybe it is possible, but it would be a function of where the relief pressure on the HST was set too low so that sufficient pressure could not be developed in the HST pump to cause the wheels to spin. And this would not be a problem with horsepower normally, but how the relief valve is set. A 25 horsepower engine should be able to "grenade" the pump of any HST tractor if the relief valve was set high enough and the load on the pump was enough. Say the wheels were chained down to the ground and cannot turn, and the relief valve is totally bypassed, and you apply 25 horsepower to the pump, something is going to give. Shaft, pump housing, something is going to go boom So I don't believe your scenario of pressing the "go" pedal and the tractor not moving from lack of horsepower is going to happen. 25 horsepower or 250 horsepower.

A CK25 has more traction than it had go. It's the only tractor I've ever used that was like that. I didn't use to like it, but I've realized it's not that bad. Without looking up specs and going off memory it seems that it outweighs the OP's base tractor by about 1000 pounds. It might not have the power to break traction which means I was unable to harness some of the pulling power, but with all other variables being equal it will out pull the OP's tractor. The best of both worlds would be a lower gear ratio so it could harness all available traction.

 

[MtnViewRanch]

I'm fine with moving slowly as long as I'm moving. This tractor weighs 2459 lbs, Fill the tires, add wheel weights and a well fed driver should be over 3,000 Lbs. To me hypothetically if I chained the tractor to an unmovable object, on dry pavement in low range, 4WD engaged, rear axle locked when you press the HST pedal, the tires should spin. If they don't than the traction exceeds the power (Torque specifically) and more power could be useful. If the tires do spin more HP would not help at all.

So no loader? With a loader the tractor is 3233lbs. Add your additional weights and it will be over 4000lbs. :thumbsup:

 

[ModMech]

You will never complain that you have too much horsepower. You will however be unhappy with a tractor that doesn't have enough.

I disagree! Our 24HP (18PTO) tractor has enough power to do EVERYTHING we need it to do, I would be VERY displeased if we had a 32 HP tractor because it would actually be too large for mowing and use a LOT more fuel - both completely unnecessarily.

 

[ericm979]

PTO chipper will be fine with 25 hp. The feed size on mine (Woodmaxx 8H) is small enough that in order to get it to auto feed with no issues, you are trimming down to about 1.5" (hardwood) anyway.

Wait, a Woodmaxx 8H on a 40hp pto tractor can only chip 1.5" hardwood?

I've chipped stuff larger than that with it hooked up to a 20 hp tractor.

Is that with some other wood than the 1.5" hardwood above? Is the problem with the hardwood that it's got branches and wont' feed, or that the chipper + tractor cant' handle it?

I'm trying to decide how much pto hp I need to run an 8H.

 

[Shaneard]

I disagree! Our 24HP (18PTO) tractor has enough power to do EVERYTHING we need it to do, I would be VERY displeased if we had a 32 HP tractor because it would actually be too large for mowing and use a LOT more fuel - both completely unnecessarily.

This is the PERFECT example of why they make so many models, there is no way only one could make EVERYBODY happy.

 

[dickfoster]

I'm 99% sure I'm buying a Mahendra 1526HST tractor this year. I'm am still open to other options, but I haven't found any others that compare with the price and specs I'm interested in. The particular specs I'm looking at is Bucket lift weight and 3 Point Lift weight. Still trying to fund the initiative so I'm still in the research phase. I posted another thread and no one had anything bad to say about this tractor and I've been researching this to death! For this question forget brand and lets talk Horse Power. Obviously this answer is different for different users. My use is primarily lugging. Towing, lifting, moving. I'll likely get a 60" rear snow thrower, a PTO chipper and a Post hole digger some day, but no mowing or brush hogging. If my research and understanding of it is correct, for lugging I should be totally fine with a 25 HP tractor. It's the PTO use that causes the need for more HP. Wide mowers and brush hogs (which I don't want or need) seem to cause the need for over 25 HP. I'm sure it's obvious why I prefer not to cross the 26HP line in the sand, but I don't want to pay for and maintain the Tier 4 emissions equipment. I only have 1.5 ache's of land so It's hard enough to justify this purchase, I really don't want to cross the 20K threshold. The PTO Chipper pushes the limit for 25 HP, but I burn firewood. Larger branches are good firewood for me, so I won't be chipping massive branches, just the stuff too small to log up. The worst thing would be if I hooked up one of my heavy trailers pressed the HST pedal in low range and didn't move because I did't buy enough HP! I hope I would loose traction before I ran out of power. What do you guys think?

Thanks!

You might want to look at the PTO HP requirements of the implements you are planning on and let that be your guide. It's power at the PTO more than overall HP that's more important sometimes. With only 1.5 acres to worry about the 1526 is likely adequate and it will drive most of the smaller chippers out there.