3-Point Hitch Drawbar horsepower

[critter986]

We just purchased a new 3pt quick hitch and the dealer talked about drawbar horsepower. Just wondering if it was the same as the PTO hp or if anyone's even heard of this.

 

[bigbull338]

We just purchased a new 3pt quick hitch and the dealer talked about drawbar horsepower. Just wondering if it was the same as the PTO hp or if anyone's even heard of this.

no they are 2 differant hp.1.the pto hp is the amount of hp the pto puts out.2.drawbar is the total engine hp,like 90 engine hp an 80pto hp.

 

[Grandad4]

Back in the day, tractors did mainly two things: pull stuff and run something like a thresher or sawmill off a huge belt pulley. Tractors in those days were rated by horsepower at the drawbar for pulling, and at the belt for stationary operation. The belt hp was usually quite a bit more since the old time drivetrains were not very efficient. These days at least the smaller, utility type tractors (say under 75-100 horsepower), mainly use the 3 point hitch for implements and the pto to run powered attachments, so today's power ratings typically reflect total engine hp and pto hp. But pulling power at the drawbar still means the same thing as in the old days, and it's important with big agricultural rigs and also in other situations as well.

Pto hp and drawbar hp will always be less than the total engine hp due to mechanical losses. Don't know if there's a set formula to relate the different measurements because that could vary by tractor, but drawbar hp is probably going to be somewhat less than pto hp due to additional friction losses of the drivetrain.

 

[kuboman]

There are usually 3 ratings
engine
pto
drawbar.

Engine hp is measured at the flywheel and is the maximum hp the engine produces.
pto hp is just that measured at the pto. Important for pto driven equipment.
drawbar hp is the hp measured by what the tractor will pull.

As a general rule there is a 15% loss from engine to pto power and another 15% from pto to drawbar. This is quite general but it gives you an idea if you are only given one figure and you want to know the other 2.

 

[PHILIP8N]

no they are 2 differant hp.1.the pto hp is the amount of hp the pto puts out.2.drawbar is the total engine hp,like 90 engine hp an 80pto hp.

No. Bad information from BB338.

Kuboman gave a great explanation.

Engine or net hp is what is available from the engine flywheel.

PTO is hp available at the pto shaft. Engine or net minus drivetrain losses. This will be different for gear or hydro. This will always be lower than engine or net hp.

Drawbar is what the tractor can pull at drawbar. Combination of engine hp, traction (slip %), and weight. Traction (slip %) and weight have huge influence here. Important for pull type implements. Plow, disc, etc. This will always be lower than pto hp.

Look up Nebraska tractor test for much more detailed information.

Philip.

 

[SLHawkins]

TractorData.com ( TractorData.com - information on all makes and models of tractors) is a good source of info for basic tracor data to include PTO and drawbar HP. Much of it comes from Nebraska Tractor tests.

Hawk