The 4.0 came out just before DaimlerChrysler broke up and Chrysler ended up with Cerberus. Based on the existing 3.5 V6, it generated 253-255 hp (190 kW), with 262-275 lb-ft of torque; compared with the 3.5, it had a slight horsepower edge, a bit more torque, and a wider torque curve for greater driveability.
Despite its large size and strong torque — perhaps because of its strong torque, which allowed higher gearing — gas mileage was actually higher than the 3.3 or 3.8 liter minivan engines, after the first year of production. Part of this likely came from its more advanced design, which included four valves per cylinder, vs the 3.3/3.8’s two.
The 4.0 engine was used in minivans and the 2007-08 Chrysler Pacifica crossover with a new six-speed automatic (62TE); it was also used in the rear / four wheel drive Dodge Nitro, with a Mercedes five-speed automatic.
The engines were essentially stopgaps; the 4.0 line closed in 2010. Based on the original 3.3 liter V6 launched in 1990, it was the last of the original family of Chrysler V6s. All were produced at Trenton Engine North.
The longer stroke helped low-rpm torque, for quicker response around town. In the Pacifica crossover, it generated 255 hp @ 6000 rpm and 265 lb. ft. of torque @ 4200 rpm. It had less noise and vibration than the advanced 3.5 it replaced.
Refinement from the 3.5 was focused on vibration at the powertrain mounts, crank shaft torsionals, and induction snorkel noise. Changes included new main bearing diameters, lower reciprocating mass piston and rod assemblies, a different block and oil pan structure, reduced bearing clearance, low-rumble intake, and an equal-length dual exhaust. For the 2007 Chrysler Pacifica, accessory drive and front bearings were changed as well.
The 4.0-liter V-6 was a single overhead camshaft, 24-valve engine, using a semi-permanent mold cast aluminum block with iron liners and cast aluminum cylinder heads, and cross-bolted main bearing caps. Like other Chrysler engines of the time, the 4-liter had electronic sequential multi-port injection (SMPI).
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