Compare/Farmall 666 vs Farmall 756

Farmall 666 vs Farmall 756

Verdict: Farmall 666 vs Farmall 756

The Farmall 666 and the Farmall 756 are both tractors — here is how they stack up on the figures that matter. Farmall 756 leads on rated power with 76 hp against 75 hp. Farmall 756 is the lighter machine (3,787 kg vs 6,780 kg), which helps on soft ground and transport, while the heavier model carries more ballast for traction-limited draft work. Farmall 666 is the newer design (1972 vs 1967). In short: choose the Farmall 756 for outright pulling power, or the Farmall 666 if a tighter budget and lighter footprint matter more. Compare the full spec tables below before booking a demo.

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Tell us about your operation

Acreage600 acBudgetMain crop / use

Fit & specs

Farmall

Fit score

Best match

Clear

Farmall

Fit score

Best match

Clear

Rated power

75 hp

76 hp

Confidence

40%

Guide price

—

Overview

Manufacturer

Farmall (a part of International Harvester)Reference

Diesel hydrostatic 2WDNovember 14 - December 3, 1973Link: Nebraska Tractor Test 1155 fileReference

The Torque Amplifier (TA) provides a power shift from direct drive (DD) to a lower speed for every gear and range.Reference

Total built

9,367Reference

—

Original price

$11,875Reference

—

Steering

—

hydrostatic powerReference

Engine

Gas Fuel tank

124.9 LReference

—

Diesel Fuel tank

117.3 LReference

—

Engine (gross)

55.9 kWReference

—

Drawbar (claimed)

40.3 kWReference

50.7 kWReference

Drawbar (tested)

43.3 kWReference

50.3 kWReference

Displacement

4.8 LReference

Bore/Stroke

95 x 112 mmReference

Power (gross)

55.9 kWReference

—

Fuel system

direct injectionReference

—

Air cleaner

dual stage dryReference

dual dry elementsReference

Compression

7.5:1Reference

7.6:1Reference

Rated RPM

2000Reference

2300Reference

Starter volts

12Reference

Coolant capacity

19.9 LReference

Power at rated engine speed

51.8 kWReference

57.1 kWReference

Max power

39.6 kWReference

49.0 kWReference

Fuel tank

—

147.6 LReference

Oil capacity

—

64.4 LReference

Transmission

Torque-AmplifierReference

Torque AmplifierReference

Gears

10 forward and 2 reverseReference

16 forward and 8 reverseReference

Clutch

dry discReference

PTO & Hydraulics

PTO (claimed)

51.5 kWReference

57.0 kWReference

PTO (tested)

51.9 kWReference

57.1 kWReference

Type

two-speed power shiftReference

Pump flow

45.4 lpmReference

—

Rear Type

IIReference

2Reference

Rear PTO

independentReference

Rear PTO Type

540 (1.375)Reference

540/1000Reference

Power at rated PTO speed

48.8 kWReference

53.5 kWReference

Engine RPM

—

1000@2100Reference

Dimensions

Wheelbase

261 cmReference

266 cmReference

Weight

6780 to 7420 poundsReference

3787 kgReference

Front tire

7.50-16Reference

6.50-16Reference

Rear tire

15.5-38Reference

Ag front

7.50-16Reference

6.50-16Reference

Ag rear

15.5-38Reference

Length

408 cmReference

416 cmReference

Width

220 cmReference

233 cmReference

Height (steering wheel)

195 cmReference

208 cmReference

Shipping weight

3365 kgReference

3787 kgReference

Clearance (front axle)

53 cmReference

—

Clearance (drawbar)

35 cmReference

—

Front tread

142 to 203 cmReference

—

Rear tread

127 to 243 cmReference

—

666 Serial Numbers

1972

7500Reference

—

1973

8200Reference

—

1974

11585Reference

—

1975

13131Reference

—

1976

15739Reference

—

Location:

Clutch housing, right sideReference

Clutch housing, left side.Reference

Electrical

Charging system

alternatorReference

Battery volts

12Reference

6 (diesel)Reference

Charging amps

—

55Reference

Batteries

—

2 (diesel)Reference

Battery AH

—

130 (diesel)Reference

Test results

Fuel use

20.1 l/hourReference

22.0 l/hourReference

Max pull

3769 kgReference

3804 kgReference

Variants

IH 756

—

standard chassisReference

Farmall 756

—

row-crop chassisReference

756 Custom

—

economy modelReference

Farmall 756 attachments

756 Serial Numbers

1967 (Farmall)

—

7501Reference

1968 (Farmall)

—

9904Reference

1969 (Farmall)

—

14125Reference

1970 (Farmall)

—

17832Reference

1971 (Farmall)

—

18374Reference

1967 (IH)

—

7501Reference

1968 (IH)

—

7672Reference

1969 (IH)

—

8164Reference

1970 (IH)

—

8284Reference

1971 (IH)

—

8427Reference

Speeds

Fit score weighs budget, operation size, crop match and data confidence against the details above. It’s guidance, not advice — always confirm with a dealer demo.