useable HP?

[MrJoe]

Good Day to All - I'm sure this has come up before but - can someone explain the horsepower ratings I find in the Kubotas? A dealer tells me a 18 hp 7510 will pull a 23 hp BX 2230 across the lot. Bout the same weight, same 3 cyl. motor. Different gears? Better torque curve? One fellow told me the BX has to be at readline to get the 23 hp, the larger B series will produce the same hp at much lower rpm. My wife says it dosn't make sence and for once I agree with her. Any easy to understand answers?
Thanks, Joe

 

[JWE]

HP is HP... If the 7510 will out pull the BX it is because the 7510 has larger front and rear tires (traction) more than HP. You will lose traction before you will stall either engine at full throttle. Engine HP or torque curves are usually not the most important considerations when selecting the right tractor for the work environment. I think that it is safe to say that the tractor manufacturers do a good job sizeing the power plant to the tractor model.

John

 

[jpr62902]

There have been several excellent discussions here on HP relevance/meaning, and what I've gleaned from them is that HP numbers are largely irrelevant when trying to discern what the true "power" of a tractor is. I think the more relevant number is the torque produced by the tractor. The BX22 has a 54.8 cu. inch motor which generates 40.5 ft/lbs of torque at about 3200 RPM (per Kubota). On the other hand, the B7500's motor is closer to 62 cu. inches and the HP is rated at much lower RPM's (I'm guessing around 2600?). I don't have the torque specs but I be willing to speculate its around 45 ft./lbs. or so, hence the more power in the B7500.

 

[To20Chris]

When it comes to pulling, if you have enough hp to overcome the available traction (a function of tires, terrain, and weight), then more will do you no good. Both the BX and B have more than enough for that, so the B wins. If you need to drive some power consuming device off the PTO (blades through grass), then that is what the extra power is for. Big mower blades use a lot of power.

 

[cckjone]

I feel the HP wars, especially among the CUTs, are mostly a lot of marketing hype. Look at the Garden Tractors sold by Sears for example. They come with 25+ horsepower motors but that certainly doesn't translate into anything meaningful.
Last winter when the old Sears GT got bogged down in a snow drift it was my neighbor, out exercising his sled dogs, who was able to pull me back out.

Does that mean 4 dog power is more powerful than 22 horsepower? Huskies…those are some unbelievably strong critters!