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The American Motors Corporation straight-4 engine was used by a number of AMC, Jeep, and Dodge vehicles from 1984 through 2002.

• For an outline of all engines used by AMC see

Main article: AMC Engines

Contents 1 2.5 L Straight-4 2 Specifications 3 Applications 4 See also

The 2.5 L inline-4 was a shortened version of the 258 6-cylinder engine bored to 3.88 in (99 mm) and de-stroked to 3.19 in (81 mm). The block is basically the same as the 258 with a larger bore and the two center cylinders removed. The head featured a new combustion chamber and port design which was later used on the 4.0L -- the 2.5L I-4 head was stretched by two cylinders in the center.

Instead of the standard AMC bell housing bolt pattern, AMC/Jeep engineers adopted the General Motors small V6 and four cylinder bolt pattern (commonly used with GM's transverse-mounted powerplants) for their new engine, because the 2.5 replaced four-cylinder engines which had been purchased from GM; and because AMC continued to buy 2.8 L V6 from GM until the 4.0 L I6 was introduced in 1987. The four-cylinder and V6 shared the same drivetrain components, whereas stronger transmissions were needed for the 4.0 L.

The AMC I4 appeared in 1984 with the new XJ Cherokee and was produced through 2002 for the Jeep Wrangler and Dodge Dakota pickup, which used the AMC/Jeep designed four since 1996.

Bore x Stroke: 3.88" x 3.19"

Displacement: 150ci (2.5L)

Valvetrain: eight valves (overhead)

Main bearings: five

Compression ratio: 9.1:1 to 9.2:1 depending on year

Output the final year was 120 hp (89 kW) at 5400 RPM and 145 ft·lb (197 N·m) at 3250 RPM using sequential mulitple-port fuel injection. For comparison, the I-6 258 provided 112@3200 horsepower and 210@2000 lb-ft of torque in its final year with the computer controlled carburetor.

For several years, the engine was detuned for the Wrangler; from at least 1992 to 1995, it produced 130 horsepower and 149 lb-ft of torque with 9.2:1 compression in the Cherokee and Comanche. ^[1]

AMC 150/2.5	Compression	Horsepower	Torque
1 bbl	9.2:1	105@5000	132@2800
TBI	9.2:1	117@5000	135@3500
MPFI	9.1:1	123@5250	139@3250

1. ^ Allpar

This engine was used in the following vehicles:  

• 1984-1986 Jeep CJ-7
• 1983.5-1984 AMC Eagle
• 1984-2000 Jeep Cherokee (XJ)
• 1987-2002 Jeep Wrangler (YJ/TJ)
• 1988-1989 Eagle Premier
• 1996-2001 Dodge Dakota

• AMC Straight-6 engine
• AMC V8 engine
• AMC Engines
• AMC/Jeep Transmissions
• List of Chrysler engines

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