do most other trucks, and the Cherokee mounted them on top of the axle. There was also a heavy duty Metric Ton package for the long-bed models. The package included heavier-duty leaf springs and wheels, larger tires, and upgraded the rear axle to a Dana 44, which increased the stock payload (cargo) capacity from , well above that of any other mid-size truck. The Metric Ton Comanche's payload rating was higher than that of many full-size pickups. Drivetrain The inaugural 1986 model year Comanches could be equipped with one of three engines: AMC's 2.5 L four-cylinder as standard, with General Motors' 2.8 L V6 or Renault's 2.1 L I4 turbo diesel available as options. In base trim the four-cylinder engine was backed by a four-speed manual transmission, with either a five-speed manual or three-speed TorqueFlite A904 automatic built by Chrysler as an option. The V6 engine was available with either the five-speed manual or the automatic, while the turbodiesel was only available with the five-speed. The V6 was the same engine used in the competing Chevrolet S-10, and equipped with a two-barrel Rochester carburetor instead of the four-cylinder's electronic throttle-body fuel injection system the optional six-cylinder was slightly less powerful than the standard four. The V6 thus offered little performance advantage over the base engine while penalizing the owner with poorer fuel economy. In the truck's second year on the market the V6 was replaced by AMC's new fuel-injected 4.0 L straight-six that developed and : 50% more power and 47% more torque than the previous V6. The new six-cylinder was also more fuel-efficient. The performance of the base 2.5 L engine was also improved with a new air intake, raising peak output to 121 hp and 141 lb⋅ft. The slow-selling turbodiesel option was dropped during the model year. Concurrent with introduction of the new straight-six a new four-speed automatic built by Aisin-Warner replaced the former Chrysler three-speed. The 30-40LE featured electronic controls with a switch on the dashboard allowing the driver to choose between two performance modes: "Power", in which the transmission downshifts more quickly and upshifts at higher rpm during hard acceleration, and "Comfort", in which the upshifts are made at lower engine speeds to conserve fuel and reduce engine noise and vibration. In 1988 output of the 4.0 L engine was improved slightly to 177 hp and 224 lb⋅ft. Chrysler purchased AMC in 1987, and by the