The Kubota ZD21 machine engine horsepower found is 21 hp. PTO horsepower found is 19.4 hp.
Engine HP21 hp
PTO HP19.4 hp
Power / weight15.1 hp per 1,000 lb
Kubota ZD21 Horsepower Specs
Engine horsepower
21 hp
PTO horsepower
19.4 hp
Rated engine RPM
3,200 rpm
Engine displacement
47.5 cu in (0.78 L)
Engine cylinders
3 cylinders
Engine
Kubota 778cc
Operating weight
1,393 lb (632 kg)
PTO-to-engine ratio
92.4% of engine horsepower
Power-to-weight
15.1 hp per 1,000 lb
Horsepower class
mid-power mower / garden tractor
Horsepower Benchmarks
Engine horsepower benchmark
This model
21 hp
Average
23 hp
Low
12 hp
High
40 hp
PTO horsepower benchmark
This model
19.4 hp
Average
18 hp
Low
8 hp
High
35 hp
Operating weight benchmark
This model
1,393 lb
Average
1,200 lb
Low
500 lb
High
2,600 lb
Power-to-weight benchmark
This model
15.1 hp/1k lb
Average
20 hp/1k lb
Low
12 hp/1k lb
High
35 hp/1k lb
Benchmarks are general reference ranges for lawn and garden tractors and mowers.
Kubota ZD21 Horsepower FAQ
Engine horsepower
The Kubota ZD21 machine engine horsepower found is 21 hp. Use engine horsepower for comparing engine output, not necessarily implement power at the PTO.
PTO horsepower
The PTO horsepower found for the Kubota ZD21 is 19.4 hp. PTO horsepower is the more useful figure when sizing PTO-driven implements.
Horsepower class
The Kubota ZD21 is listed as mid-power mower / garden tractor based on the engine horsepower found.
Rated engine RPM
The rated engine speed found for the Kubota ZD21 is 3,200 rpm. This is the engine speed used for the listed power rating.
Engine specs found
Engine specs found for the Kubota ZD21 include Kubota 778cc, 47.5 cu in (0.78 L) displacement, and 3 cylinders.
Operating weight
The operating weight found for the Kubota ZD21 is 1,393 lb (632 kg). Weight matters because the same horsepower feels different in a light mower than in a heavy tractor.
PTO-to-engine horsepower ratio
The PTO-to-engine horsepower ratio for the Kubota ZD21 is 92.4% of engine horsepower based on the figures found.
Power-to-weight
The calculated power-to-weight figure for the Kubota ZD21 is 15.1 hp per 1,000 lb based on the engine horsepower and operating weight found.
Horsepower planning note
The practical split on the Kubota ZD21 is engine power at 21 hp and PTO power at 19.4 hp.
Official information note
Mistakes do happen. Check the operator manual, service manual and official kubotausa.com website for official horsepower, PTO horsepower, engine RPM, torque and operating-weight specifications before buying implements or servicing the machine.
