Tractor Sizing How much HP do I really need?

[BrokeFarmerJohn]

My John Deere LX255 Lawn tractor seems to have a really nice feature built into the hydro. I've towed super heavy loads with this little deere up that same driveway. On the deere you could mash the pedal to the floor and when the hill was encountered, the tractor would slow down, but still climb the hill. It appears there is some governor on the hydro swash plate that automatically "gears down" based on load regardless of the pedal position. On the Deere max pedal always delivered max power and max speed possible given the load. Never would lifting the pedal help. It would never ever stall. I've pulled such heavy trailers up that driveway that sometimes the tires would just break loose on dry pavement halfway up, but it would never stall. Clearly I need to learn how to lift as this tractor does not have this magic feature.

As for actually testing mine on a dyno, would an automotive dyno work? I know some race shops near by with dynos from my racing days decades ago. I would love to prove this one way or another.

Thanks

Just did a little math, your LX255 has 15hp and 25.3 lb-ft, weights 483lbs, that's 19.32lbs per HP.

The 1526 has 26hp and weights 2440lbs, that's 93.84lbs per HP.

The Mahindra just pulling its own weight is doing 5 times more work then the garden tractor was but in high gear is traveling twice as fast.

Garden tractors don't have ranges, running a garden tractor with the peddle to the floor pulling a trailer is comparable to working the Mahindra in low range with the peddle to the floor, both traveling around 3mph.

I think your expectations for this tractor are WAY too high. I'm not sure where the expectation of zipping up hills in high range or that you could work it in high range going 10-15mph came from, I hope the dealer didn't lead you on in anyway.

Tractors do lots of work at low speeds, usually under 5mph. high range is just for travel, if it can't climb it in high, gear down to mid range, simple as that.

Your not gonna find a tractor that performs well in high range, your tractor climbs hills better than most from what I have read about the 1500 series Mahindra's.

For an example, I have a cabbed JD 4320, it's 48.1hp, my tractor with the cab and FEL weights around 5300lbs, that's 110.4lbs per HP, if I fill the rears or add more ballast that number will go up. If I filled the rear tires that would add 500lbs, if I added a ballast box another 500lbs, now were up around 131lbs per HP. The mindset of tractors is traction and torque, guys weigh there tractors down for better traction, we don't try to speed them up.

 

[Roger66]

I think we’ve beat this horse enough and I think we can close this thread.

As a first time tractor buyer, what I’ve learned:
My expectations were too high.
My test drive was not nearly comprehensive enough.
Don’t take anyone’s opinion on how much HP is enough, evaluate first hand on the test drive.
Less pedal yields more power on a basic Hydro unlike some lawn tractors like mine.
If the power is in question a PTO Dyno is the way to validate.
A 25 HP tractor can do lots of work, but the power is limited and must be used properly.
If you came from a “performance” Car or Truck background be ready for compromise.

 

[Shaneard]

I think we’ve beat this horse enough and I think we can close this thread.

As a first time tractor buyer, what I’ve learned:
My expectations were too high.
My test drive was not nearly comprehensive enough.
Don’t take anyone’s opinion on how much HP is enough, evaluate first hand on the test drive.
Less pedal yields more power on a basic Hydro unlike some lawn tractors like mine.
If the power is in question a PTO Dyno is the way to validate.
A 25 HP tractor can do lots of work, but the power is limited and must be used properly.
If you came from a “performance” Car or Truck background be ready for compromise.

Well said.

 

[Roger66]

I think we’ve beat this horse enough and I think we can close this thread.

As a first time tractor buyer, what I’ve learned:
My expectations were too high.
My test drive was not nearly comprehensive enough.
Don’t take anyone’s opinion on how much HP is enough, evaluate first hand on the test drive.
Less pedal yields more power on a basic Hydro unlike some lawn tractors like mine.
If the power is in question a PTO Dyno is the way to validate.
A 25 HP tractor can do lots of work, but the power is limited and must be used properly.
If you came from a “performance” Car or Truck background be ready for compromise.

I forgot to thank everyone for all of your participation in this thread!!! I also want clarify that I intend no fault to my dealer or the brand. My only real compliant is with the government imposed regulations. Even if one color or another has a few more or less Ft-lbs. of torque. I'm sure i would have had the same experience the whole rainbow at the 25HP power level, I'm looking for an order of magnitude more power not a couple of percent (if there even is a difference).

Thanks again all for your input!

 

[mike69440]

I think ideal ample power for a tractor gear type transmission is 1 HP per 100 lbs total weight, with a HST, 1 hp per 80 lbs of operating weight. (Tractor, attachments, and Implements) The ratio weight to HP can go up slightly for large tractors can go up slightly, except for heavy field work.

My L39 is slow turtle on hills roading at 40 Hp and 8000 lbs. Even fueled up a bit, and torquey for its power, 5 mph roading on a moderately steep hill is slow. I would be nice to pull near 10 MPH up a grade. Snow plowing needs power also. Field work needs power.

 

[CalG]

On 1.5 acres, 25hp will be more than enough tractor. things get crowded on a small place.

 

[AGTtactical]

I think ideal ample power for a tractor gear type transmission is 1 HP per 100 lbs total weight, with a HST, 1 hp per 80 lbs of operating weight. (Tractor, attachments, and Implements) The ratio weight to HP can go up slightly for large tractors can go up slightly, except for heavy field work.

I think this is the best bit of information in this entire thread. Interestingly, Kubota seems to agree. I built a spread sheet to compare my tractor choices, and every model (all HST) had a lbs/hp under 80...most were in the 65-75 range, before adding an implement or loader.

 

[searcyfarms]

so sorry about your situation with your tractor - that is what I call the most maddening thing that can happen - not enough power - I have had that sick feeling before when trying to go up a hill and then not being able to make it and then the empty pit in my stomach as I break into a cold sweat wondering how bad the wreck is going to be when I am upside down and stopped in the wreckage at the bottom, or when I crest the hill and didn't realize my load was bigger than my tractor weight and brakes combined.

I have to say I have only had one of those pucker events end up in a wrecked tractor/trailer of hay - the ole ford selectospeed - now sure the size of the tractor that it was in but the hay weighed more than the brakes/tractor could stop so we ended up for a wild ride with a spilled load, jackknifed tractor/trailer, and ford on its side. none of us were hurt but boy it scared the youth right out of us.

If you are trying to get firewood up the hill, be careful, the best advice several ole farmers gave me was be it a hill/mudhole - get a run at it!!! horses are smart they do the same thing!!!!

Are you smart or wise, the smart guy loads the trailer full and doesn't get there, the wise man makes more trips!!!

You will learn the abilities of your machine in each category of work, that is the beauty of it, you can still do a lot just have to plan accordingly - just respect the limitations and you will be safe.