7 material differences · fewer than 12

Tractor oneInternational Harvester 15661974–1976No measured PTO figureTractor twoInternational Harvester 37881979–1981No measured PTO figure

Which should you choose?

We will not advise between these two machines, because the drive differs (Two-wheel or four-wheel drive; 4WD); they were not built in overlapping years (1974–1976; 1979–1981). The figures below are side by side so you can judge them yourself; each says whether it was measured, claimed or declared by its source.

Field by field

7 material differences · 4 fields identical or within 5%, which is not counted as material

International Harvester 1566 and International Harvester 3788, field by field
Field15663788Gap
Engine
Engine power, claimed claimed161 hp170.6 hp+6% 3788
Engine declaredINTERNATIONAL HARVESTER DT-436INTERNATIONAL HARVESTER DT-466 Bdiffers
Displacement declared7.14 L7.64 L+7% 3788
Transmission
Top speed declared18.6 mph · 30 km/h18.6 mph · 30 km/h—
Clutch declaredPedal-operated ceramic clutch——
Hydraulics & hitch
Pump flow declared12.0 gpm · 45.5 L/min12.0 gpm · 45.4 L/min—
Rear PTO speeds declared1000 rpm1000 rpm—
Weight & dimensions
Unladen weight declared15,194 lb · 6,892 kg18,620 lb · 8,446 kg+23% 3788
Wheelbase declared104.8 in · 2,662 mm110.0 in · 2,794 mm—
Length declared168.0 in · 4,267 mm228.0 in · 5,791 mm+36% 3788
Width declared112.0 in · 2,845 mm101.6 in · 2,581 mm+10% 1566
Ground clearance declared17.0 in · 432 mm23.2 in · 589 mm+36% 3788
Turning radius, braked declared11.9 ft · 3.63 m——
Fuel tank declared168.0 qt · 159.0 L360.0 qt · 340.7 L+114% 3788

Height is not in this table. It is not one measurement: the sources measure it to different points — over the cab on some machines, over the steering wheel or the exhaust on others — and the same tractor measured two ways can differ by most of a metre. It appears here only when both machines' figures carry the point they were measured to and it is the same point, which is not the case for these two. Each machine's own page prints its height as its source gives it.

International Harvester 1566 sources

Source
  • Source: Traktorenlexikon, “Farmall Farmall 1566”
  • Source: Traktorenlexikon, “IHC 1466”
  • Source: Traktorenlexikon, “IHC 1566”

International Harvester 3788 sources

Source
  • Source: Traktorenlexikon, “IHC 3788”
  • Source: Traktorenlexikon, “IHC 3588”