With more than 160,000 miles on the 4.0L I-6 in our 1997 Jeep Cherokee, engine performance and reliability are not as great as they once were. The engine suffered from various gasket and seal leaks, ...

The Jeep 4.0L engine found in TJs, XJs, ZJs, and WJs is a trusty powerplant, and the '91-and-newer high-output versions make respectable power for a long time if well cared for. We recently ran across ...

The power of a V8 from a 4.0L 2-cylinder boxer engine 35% fuel economy saving 15-30% cost saving versus current engines 52% thermal efficiency It goes without saying that automotive history is ...