• Rigid chassis
  • WhichTractor size: Standard-size
  • No lab test on file
  • 1976–1980
  • 6,150 built

WhichTractor size, not the maker’s category

Derived by WhichTractor from a sourced three-point linkage. How we decide what a machine is

International Harvester 686 specs: hp, weight, years

INTERNATIONAL HARVESTER C-291 six-cylinder. The manufacturer claimed 66.1 horsepower. No laboratory has tested one, so there is no measured figure at the shaft.

Engine power, claimed · gross or net not stated

66.1 hp

49.3 kW as stated by the source

No lab test on file

Claimed · standard not stated by the source

Source · Traktorenlexikon, “IHC 686”, claimed

This is the maker’s own figure, measured at the engine. Power at the PTO is lower — by how much, for this machine, nobody has measured.

Weight
8,199 lb
Hyd. flow
12.0 gpm
Top speed
18.6 mph

International Harvester 686 specs: key facts

  • The International Harvester 686 was built from 1976 to 1980.

  • The International Harvester 686 has a claimed engine power (gross or net not stated) of 49.3 kW (66.1 hp); it has no measured PTO figure.

  • The International Harvester 686 is two-wheel drive (2WD).

  • The International Harvester 686 has a INTERNATIONAL HARVESTER C-291 engine, a 6-cylinder unit.Source 1

  • The International Harvester 686 weighs 3,719 kg (8,199 lb) unladen.

  • The International Harvester 686 has a rear PTO running at 540 rpm.

  • The hydraulic pump of the International Harvester 686 delivers 45.5 L/min (12.0 gpm).

Source · Traktorenlexikon, “IHC 686”

How does the 686 compare with its class?

  • Strength:

    A maximum engine torque of 298 N·m is high for its class — 24% above the median of 240 N·m across the 289 machines within 10% of its power that hold this figure.

  • Limitation:

    Five forward gears is low for its class — 58% below the median of 12 across the 340 machines within 10% of its power that hold this figure.

  • Strength:

    A 117 L fuel tank is high for its class — 47% above the median of 80 L across the 324 machines within 10% of its power that hold this figure.

  • Worth knowing:

    An unladen mass of 3,719 kg is high for its class — 31% above the median of 2,840 kg across the 347 machines within 10% of its power that hold this figure.

Derived by WhichTractor from 347 comparable records. How we work this out

Illustration of the 1976–1980 International Harvester 686, a 66 hp farm tractor, a drawing generated from its specification record
Illustration — not a photograph

How much horsepower does a 686 have?

The only figure for the 686 is 66.1 hp (49.3 kW) of claimed engine power, gross or net not stated, no test standard stated — not power at the shaft.

Engine, claimed (gross/net not stated)
66.1 hp

Source · Traktorenlexikon, “IHC 686”

What engine is in a 686?

A 686 has an INTERNATIONAL HARVESTER C-291, a 6-cylinder engine.

Engine — 686 engine specifications
Make & modelINTERNATIONAL HARVESTER C-291Source 1
Cylinders6, liquid-cooledSource 1
Max torque220 lb·ft · 298 N·m @ 1,600 rpm
InjectionBosch injection pump
Electrical system12 V

Source · Traktorenlexikon, “IHC 686”

How much will a 686 lift, and what is its hydraulic flow?

Hydraulic and PTO specifications for the 686 are below.

Hydraulics & PTO — 686 hydraulics and PTO specifications
Pump flow12.0 gpm · 45.5 L/min
Hitch categoryCategory 2
Rear PTO540 rpm @ 1,650 engine rpm
PTO shaft1 3/8" - 6 splines

Source · Traktorenlexikon, “IHC 686”

What transmission does a 686 have?

Transmission specifications for the 686 are below.

Transmission — 686 transmission specifications
Clutchpedal-operated dry single-plate clutch
Top speed18.6 mph · 30 km/h

Source · Traktorenlexikon, “IHC 686”

How much does a 686 weigh?

A 686 weighs 8,199 lb (3,719 kg) unladen.

Weights & dimensions — 686 weights and dimensions
Unladen weight8,199 lb · 3,719 kg
Wheelbase103.0 in · 2,616 mm
Length162.0 in · 4,115 mm
Width89.4 in · 2,271 mm
Height105.0 in · 2,667 mm
Ground clearance21.0 in · 533 mm
Front track58.0–82.0 in · 1,473–2,083 mm
Rear track56.0–96.0 in · 1,422–2,438 mm
Turning radius, braked12.0 ft · 3.66 m

Source · Traktorenlexikon, “IHC 686”

What oil does a 686 take, and how much?

A 686 engine takes 10.7 qt (10.1 L). Single source, not independently verified — always confirm against the operator’s manual for your machine.

686 fluid capacities, grades and service intervals
SystemCapacity
Engine oil10.7 qt · 10.1 LSource: Traktorenlexikon, “IHC 686” · single source, not independently verified
Cooling system21.0 qt · 19.9 LSource: Traktorenlexikon, “IHC 686” · single source, not independently verified

Always confirm against the operator’s manual for your machine before service.

Which tractors compare with a 686?

Within 10% of its 66.3 hp at the PTO as the maker claimed it, with no laboratory test on file, the same type, and first built within 15 years of it.

Common questions about the International Harvester 686

Is a 686 two-wheel drive or four-wheel drive?

The International Harvester 686 is two-wheel drive (2WD).

What PTO does a 686 have?

A 686 has a 540 rpm rear PTO on a 1 3/8" - 6 splines shaft.

Sources and how this page was built

Compiled from Traktorenlexikon, “Farmall Farmall 756”; and Traktorenlexikon, “IHC 686”.

Sources checked

14 SEP 2026

Spotted an error?

Sources

Facts taken from these documents, units converted. Numbers beside a figure refer to this list. Licences and attribution

  1. Traktorenlexikon: Farmall Farmall 756 — CC BY-SA 4.0, WIKIBOOKS-TL-118751 · revision 1054991. Wikibooks contributors (Traktorenlexikon). Original document
  2. Traktorenlexikon: IHC 686 — CC BY-SA 4.0, WIKIBOOKS-TL-118937 · revision 1035394. Wikibooks contributors (Traktorenlexikon). Original document