hp/net hp/pto hp

ALBALD1 · Jan 8, 2005

From reading on here, it seems most people say 30hp is minimum for 5ft implements(tiller,brush hog,etc) & under 30hp for 4ft implements. However, most tractors have 2-3 different hp ratings. example. kubota website specs say b2910hst has 30gross hp & 22 pto hp. some specs even have a 3rd rating, net hp. What hp rating do you look at to figure what size implements?

Surge · Jan 8, 2005

ALBALD1

First, welcome to the TBYNET forum... you will learn so much from all the knowledgable people here...

Oh, if it were only so simple on matching horespower to implement size ... because the size of the tractor also comes into play....

Your question dealt with not only the HP specification, but also type and size of implement. Two different issues to contend with...

First on the horsepower issue... Certainly the amount of horsepower the engine is rated at is a guideline... Generally, the engine is rated at the "peak" horsepower and RPM.... sometimes this is measured at the "Flywheel" like a lawnmower or garden tractor mower.. You know, says a 22HP Briggs and Stratton motor... ya but at the crankshaft, you may be getting a 1-2 HP....or in the case of net HP, generally, that is which is available to the rear wheels... that amount of horsepower varies across the RPM spectrum on all engines, gas or diesel.. The PTO HP is ofcourse another important measure and is controlled by the HP output of th engine and is that which is measured obviously at the PTO output to drive the implement...

You see the significant drop, 8 HP difference on the B2910 since power is always taken by the transmission to drive the tractor.. an HST transmission takes more power... a gear drive generally has a 3-4 HP loss to the PTO... just like an automatic versus stick shift in car due to the direct gear drive.

But the ability of which size implement, ie 4ft vs. 5ft vs. 6 ft depends on the type of implement first... If it is a PTO driven implement... PTO HP should be used as the first litmus test... ie tiller, mower etc.. however if it is a plow or blade and does not use the PTO, then the engine HP is more the determining factor..

However, all this being said, there are other important factors, such as tire style, R1 vs. R4 vs. R3....and "weight" of the tractor in combination with the tire style.

The B2910 weighs only 1760 pds...this is fairly light in even in the compact tractor world....if you were to have Turf tires on this and attempt to pull a plow you would not be able to transfer the engine power to the ground and thus the implement. If you were using a finish mower, on grass, totally different story.... If you have R1 (ag tires) you will have better traction performance to pull the plow, but again weight is an issue... Many other tractors in the 30 - 35 HP range weigh 2500 - 3000 pds or more, transferring the engine power to the ground.... Blending the correct tire and power to the tasks at hand...

Again, depends on what you want to do on the farm... if money is no object.. you can always go overkill... heavy machine, lots of power....

The B2910 I think would generally be viewed by most as a high quality somewhat light ag, gardening or landscaping machine.... you would want to move up to a heavier Kubota machine for farming chores or heavy snow situation etc.....or, look at heavier tractors in that same horsepower range like Kioti, Mahindra, Century/Branson, etc. etc...

So I really haven't specifically answered your question, but I can tell you that my 25 HP, 21 PTO rated, 2400 lb. tractor handles a 5ft blade and 5ft finishmower just fine....and drives a 48 inch tiller... but would probably not do very well with a 6ft implement of any kind due to the weight and power.....

Soundguy · Jan 8, 2005

30 hp will get you into some 6' implements.. like possible a rotary mower.. deffinately a finish mower, and a grader blade.

High 20's.. say 25 and up will be the minimum for accaptable use of 5' implements.

For instance.. my 27 engine hp 8N handles a 5' rotary mower fine in brush. Thick / tall / wet grass makes me take less than a full bite.

Soundguy

ALBALD1 · Jan 8, 2005

Thanx for the reply. I've actually been reading here for a while & planning on buying come spring. My local dealer offered the century 2535 w/ fel at 14500 & the backhoe is 5900. I know this is a lot more tractor than the smaller kubota. I have several projects as far as landscaping & some drainage work to do, so I was planning on getting the century. Then I thought once the initial "big work" is done, is it going to be more than I need? From the posts here, I've figured I won't be able to use it to mow the lawn due to the weight and there is a significant price difference in the 2 sizes, so I've started looking at some of the smaller tractors. however, I don't want to get something smaller & then wish I had bought something bigger. I have a riding mower, but it would be nice to have one machine to do it all. This is probably the only tractor I'll buy, so I'll probably just go w/ the bigger one & plan on keeping a mower around for the yard. Just have to come up w/ more big jobs.

BER · Jan 8, 2005

Something I noticed about my tractor: The colorful brochure from the dealer listed my tractor's engine HP at 33, but the owner/operator manual lists it at 30HP net. This might be the difference between gross/peak HP and actual/net HP. The brochure also listed my tractor's PTOHP at 26.5, but the owner/operators manual listed it at 25 PTOHP. The brochures are written to help sell tractors. Of course the last statement is only my opinion. Just more to consider.

DK35vince · Jan 8, 2005

How big is your lawn.
I would be using the Century for the big jobs plus mowing the lawn.
I use a 35 HP tractor of similar size and weight for my big jobs and as my primary lawn mower. Works just fine for me..
I went with the R-4 tires for decent traction but limit the damage to the lawn.

KiotiJohn · Jan 8, 2005

( From the posts here, I've figured I won't be able to use it to mow the lawn due to the weight and there is a significant price difference in the 2 sizes, so I've started looking at some of the smaller tractors. )
You may very well be able to mow the lawn. It depends on the type of soil you have. I have a pretty sandy soil here, and don't have a rutting problem at all with my CK20. at 1993#, and could go much larger with no problem on this lawn. I drive my motorhome on this lawn with no rutting. RedDog uses his Kioti DK65 to mow his lawn without problems.
Get a heavy tractor brought to yor house and try it there. Find out what it will do. John

ALBALD1 · Jan 9, 2005

I think I will talk to the guy about bringing one out. I haven't driven any of them & I know I need to drive them all before deciding, but I've been leaning heavily toward the century 2535 which weighs about 3400#. Been planning to buy in the spring after throwing up a shed to keep it in. The day after Christmas, the wife said I should have just gotten it for Christmas. She should have said that a week earlier.

KiotiJohn · Jan 9, 2005

( I've been leaning heavily toward the century 2535 which weighs about 3400#. )
You may want to consider getting R4 industrial tires to cut down on lawn problems. They're a good compromise between Ag and Turf tires. Also, if mowing your lawn, turn off the 4WD as that can cause damage to the lawn. John
EDIT: Dont' you just hate it when people say "I could have told you, or you should have back then!" I know you'd be doing seat time now if your wife had told you that week earlier! Happy new year, John

MMM · Jan 9, 2005

( What hp rating do you look at to figure what size implements? )

PTOhp for pto implements, DBhp for ground engaging implements. Usually around 80% and 70% of grosshp respectively. Tractor weight is a large variable in ground engaging ability and it would be best to ask other owners with similar soil makeup.