Does HST Transmission Rob Horsepower??

   #11  

CobyRupert

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Washington County, NY
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... all HST (old and new) uses a certain amount of HP just like a 5 foot mower uses less HP than a 6 footer.

....unless the 5 foot mower is traveling 20% faster than the 6 foot mower, (or conversely, the 6ft mower is traveling at 83% speed of the 5 foot mower) then they’re using the same amount of horsepower.
 
   #12  

MossRoad

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Power Trac PT425 2001 Model Year
....unless the 5 foot mower is traveling 20% faster than the 6 foot mower, (or conversely, the 6ft mower is traveling at 83% speed of the 5 foot mower) then they’re using the same amount of horsepower.
AHHHHHHH!!!!!! Math test!!! o_O
 
   #13  

crazyal

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I always love when HST comes up. You have those who are die hard gear people who think the HST guys succumbed to the dark side. Then there's the HST guys who feel like they've seen the light. I had a geared tractor (never again), have a shuttle shift, and an HST. For doing almost anything the HST is the tractor I use. For brush hogging, it's a no brainer. With HST I can set the engine at near idle, engage the PTO, rev the motor up to get the brushhog up to speed, and then go at any speed I want. If I need to slow down or turn the PTO stays at the correct speed.

I'm sure there's a point where a scut will have an engine just too small but that's what wallets are for. For those who say "more debt", so what? Spend a day or two pushing a clutch to shift gears while doing dirt work and suddenly HST looks good. Or try pulling a log with a geared tractor and have it get caught. Simply letting off the HST pedal and that's it. With gears unless your foot is near the clutch you're most likely going to stall the engine (or worse). They all work, they all do their job. But there's a reason why almost every sub 60hp tractor sold is HST.
 
   #14  

Stan B

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Muskegon, Michigan, US
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Kioti CK3510SE HST
Spend a day or two pushing a clutch to shift gears while doing dirt work and suddenly HST looks good.
HA! That's me! Sold a 1959 Oliver 550 and bought my Kioti CK3510 HST. Finally, the calf on my right leg is approaching the same size as the left leg.
 
   #16  

k0ua

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Now, lets see.... about those tires... :)
 
   #17  

Cougsfan

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Every spec sheet I have looked at where manufactures offer both a HST and shuttle shift version of the same tractor, the rated PTO HP is the same. They don't rate the HP at the rear wheel, but you could assume the HST will be lower due to inefficiency of the HST. Is that a big deal? Not usually.
 
   #19  

v908

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Agua Dulce, CA
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Yanmar F18D
HST and Gear/Shuttle are more reliable than traditional Gear/Clutch .
How so? I have 900 hours on my Yanmar with manual transmission and have only replaced the clutch once (several years ago).
 
   #20  
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Feb 12, 2021
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Livingston, East Texas Piney Woods
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Massey Ferguson 2020 MF1760M
-I heard from guys at work that the new tractors with HST transmissions rob the PTO of HP? What is the difference between HST and Shuttle Shift? Would like to buy a tractor to bush hog about 20+ years of brush overgrowth on 70 acres. I'm a fan of the FORD 10 series tractors but the new tractors seem inviting.
There are limits to how big you can go with an HST. I'm at the top of Massey's line with a 59.9 HP HST tractor. The specs say that my PTO is only 44.4 HP. That's probably measured at the PTO itself and not accounting for any losses that the driven device gearbox may impose. I went HST so that the wife etc won't have any issues operating the tractor. Otherwise, I probably would have gone up a level from a compact tractor to a utility tractor.
 
 
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