How does an HST compare in pulling power with the same tractor and a gear trans?

[4570Man]

Just look at professional tractor pullers. You need a level of spinning and digging to get down to the "good ground".

There’s a lot of difference in pulling tractors and regular tractors.

 

[LouNY]

The only hydros I can put a direct correlation to would be the IH 656 gear and hydro and the IH Hydro 100 and a IH 986.
I ran all 4 of these in the same time frame the geared tractors would outpull the hydros any and every day of the week.
On light duty jobs or light road hauls (empty wagons) the hydros were faster.
For pto work the hydros were a touch better in that you could find the perfect gear for the pto horsepower.
For light duty the hydros were as nice or nicer.
When you made them work on drawbar loads the fuel economy of the hydros was terrible compared to the gear tractors.
For chopping corn pulling a chopper and wagon the hydo version was as good or better till you got 2/3s of a load or into soft ground were you needed the drawbar pull,
then the hydros would fall flat.

As far as tractor pulling even when new the hydros couldn't hold their own even in the stock classes.

Those examples may be a bit bigger then these new compacts but I'd believe the comparison to be valid.

 

[WranglerX]

My HST can scrub all 4 tires in low range (4 WD) and dig holes and bury its self..... My pulling power out does it weight factor to cause traction....

Whats to compare?

Dale

 

[Aquamoose]

Point “A” to point “B” at one speed - geared tractor

Point “A” to point “B”, pick up a load of gravel, back up to point “C”, go to point “D” and start spreading the load between point “D” and “E” then back it up carefully between & around point “F” to park it at point “G” - HST tractor

 

[k0ua]

Point “A” to point “B” at one speed - geared tractor

Point “A” to point “B”, pick up a load of gravel, back up to point “C”, go to point “D” and start spreading the load between point “D” and “E” then back it up carefully between & around point “F” to park it at point “G” - HST tractor

I never heard it put like that, but it makes sense to me!..

 

[Waffles]

I used a 33 HP NH and LS that are virtually the same.

I tested both in a mid range gear that put them at equal speed. The HST would bog down and stop when working up steep hills. The gear didn't even notice the hill and could almost idle up it.

They are both have the same max pull force in low range as they are traction limited, even on flat concrete.

HST will do the same work, just slower than gear.

I still bought HST since I don't have enough hands and feet to: steer, shift, brake, clutch, operate loader, change throttle while navigating my constantly changing terrain.

 

[Industrial Toys]

In one sense, HST uses HP.

I don't think the question is a very valid one. Too many apples to oranges comparison. Take the same tractor model, same tires and same application, and if available in both hydro and gear, you could probably make some valid comparisons. It would have to be unbiased, as often people just defend what they have.

You almost certainly have more control over your traction with an HST, but it has other disadvantages not related to traction.

 

[K5lwq]

In one sense, HST uses HP.

I don't think the question is a very valid one. Too many apples to oranges comparison. Take the same tractor model, same tires and same application, and if available in both hydro and gear, you could probably make some valid comparisons. It would have to be unbiased, as often people just defend what they have.

You almost certainly have more control over your traction with an HST, but it has other disadvantages not related to traction.

I agree with this. I am afraid though we may never know. Kinda like how many licks to get to the center of a tootsie roll pop. :licking:

 

[k0ua]

I agree with this. I am afraid though we may never know. Kinda like how many licks to get to the center of a tootsie roll pop. :licking:

Depends on whether you "crunch" or not....

 

[LouNY]

In one sense, HST uses HP.

I don't think the question is a very valid one. Too many apples to oranges comparison. Take the same tractor model, same tires and same application, and if available in both hydro and gear, you could probably make some valid comparisons. It would have to be unbiased, as often people just defend what they have.

You almost certainly have more control over your traction with an HST, but it has other disadvantages not related to traction.

The only hydros I can put a direct correlation to would be the IH 656 gear and hydro,
the same manufacture, the same frame, the same size rubber, both gas engines,
they were doing the same work on the same farm day in and day out for well over 20 years.
Then the hydro puked and the replacement hydro never worked right.

the geared tractors would out pull the hydros any and every day of the week.
On light duty jobs or light road hauls (empty wagons) the hydros were faster.
For pto work the hydros were a touch better in that you could find the perfect gear for the pto horsepower.
For light duty the hydros were as nice or nicer.
When you made them work on drawbar loads the fuel economy of the hydros was terrible compared to the gear tractors.

I would say that those tractors were your apples to apples comparison.
I put a lot of hours on both of those tractors working them daily.

Also I believe that both of those models have Nebraska test data available if anyone cares to read up on them.

 

[Industrial Toys]

Why would the geared model out pull the hydros and day of the week? Were they hydro or torque converter transmissions? In a sense it's like asking if the same truck can pull more in gear or auto transmission versions.

 

[4570Man]

Why would the geared model out pull the hydros and day of the week? Were they hydro or torque converter transmissions? In a sense it's like asking if the same truck can pull more in gear or auto transmission versions.

They’ll pull a load faster but the max drawbar pull is about the same.

 

[Industrial Toys]

Is a hydro model heavier on the rear wheels?

 

[CobyRupert]

From some people who know more than me:
“A discrete-gear transmission will typically have an efficiency of 95% or greater, meaning that 95% of the input energy is delivered to the load (wheels). A hydrostatic transmission has an efficiency of around 80%. Some well designed units will have an efficiency slightly above 85%, but none can approach the efficiency of a discrete-gear transmission. A designer always poses the question: Does the gain in vehicle productivity offset the loss in efficiency and resultant higher fuel cost?”

Hydrostatic Transmissions Advantages | Hydraulic Pump

 

[Industrial Toys]

I guess as tractors for field work get bigger quickly, those losses become unacceptable. Also the extra heat. And noise?

 

[3gunr]

I used a 33 HP NH and LS that are virtually the same.

I tested both in a mid range gear that put them at equal speed. The HST would bog down and stop when working up steep hills. The gear didn't even notice the hill and could almost idle up it.

They are both have the same max pull force in low range as they are traction limited, even on flat concrete.

HST will do the same work, just slower than gear.

I still bought HST since I don't have enough hands and feet to: steer, shift, brake, clutch, operate loader, change throttle while navigating my constantly changing terrain.

I have mowed tall grass and brush up a steep hill with a 6 ft cutter behind a 32 pto hp hst mahindra without the slightest bog.In fact i have dug tons of dirt out of a tall bank and never came close to it bogging way down.

 

[Industrial Toys]

FWIW, I guess a lot of Dozers now have hydrostat transmissions. That kind of says something about how good they are at managing power. Despite ineficiencies.

 

[rademamj1]

Not trying to change the subject, but I just had a long discussion about this thread with a neighbor, and he brought up the subject that skid steer HST systems are powerful and smooth well into the 95HP range. Something I not familiar with. But I cannot find a single specification on any Skid Steer HST transmissions.

 

[K5lwq]

I don't think a skid steer has a transmission like a HST tractor. They use a pump that drives individual motors to drive the wheels. Similar to a zero turn mower. This gives the flexibility to have one motor going one direction while the other motor goes the other direction.

I do think this thread is a lot more informative than what I thought it would be. Good conversations.

 

[Industrial Toys]

You are correct. Just a pump and the operator controls the flow of oil (manually or by electronic means) to the hydraulic motors, one on each side.