Why tractors have 3 cylinder engines instead of a 4 cylinder engine??

Question

A 4 cylinder engine is suppoosed to be more balanced...

Answer 1

farm tractors mostly run on diesel cycle engines which typically are more efficient when utilized with odd number of cylinders. A 4 cylinder would most likely run on gasoline.

Answer 2

A 4 cylinder would be more balanced but a tractor is not necessarily built for comfort. I would guess that for the job at hand a three cylinder engine is the most efficient and that cutting down noise and vibration is not a primary concern.

Answer 3

They do.

They also have 2, 5, 6, 8, 10, 12.

Look at this horse from John Deere:



MANUFACTURER
MODEL John Deere
9620T
Official Test
Nebraska Test Number 1845

Engine
Manufacturer John Deere

Aspiration Turbo & Air-to-Air Aftercooled

Cylinders/Displacement, cu. in. (liters) 6/766 cu.in. (12.5 L)

Cylinder Liners Wet Sleeve

Fuel Tank Cap., US Gal. (L) (Open; Cab) 300

Standard 300

Optional ---

Underhood muffler ---

Performance
Advertised PTO HP (kW) @ Rated RPM 342 (255) @ 2100

Official PTO HP (kW) @ Rated RPM 324.10 (241.68) @ 2100

@ Standard PTO @ Eng RPM 363.53 (271.08) @ 1894

Maximum @ Eng RPM 374.40 (279.19) @ 1700

Advertised Engine HP (kW) @ Rated Speed 500 (373) @ 2100

Max Unballast Drwbr HP (kW) @ Eng RPM 381.79 (284.7) @ 2105

Maximum Torque (PTO) @ RPM, lb-ft (Nm) 1233 (1672) @1051

Max Torque Rise (80% Rtd Spd) @ Eng RPM 42% @ 1700

Maximum Torque Rise % (PTO) @ Eng RPM 51.9% @ 1051