Getting 400 HP Out of a 4.0-Liter Straight-Six Jeep Engine Requires a Ton of Work Especially if you're not using forced induction. By Brian Silvestro Published: Sep 21, 2020 12:52 PM EDT ...

We're rebuilding the 4.0L engine in this 2005 Jeep Rubicon Unlimited. We added new JBA headers for better exhaust flow, an Airraid throttle body spacer, and a cold air intake setup from Airaid all ...

If any engine can give a grizzled Jeeper the warm fuzzies, it's the'87-'06 Jeep 4.0L inline six. Designed by AMC and refined by Chrysler, its basic architecture was based on the '64-and-up AMC 199 ...

Jeep's 1980s era 2.5-liter four-cylinder engine didn't have a ton of power behind it, but it was incredibly reliable, something it's still known for today.

No better way to quadruple a two-valve Jeep engine's horsepower like 20 pounds of boost and water ... which an On3 Performance 7675 turbo and an air-to-water intercooler can drive as high as 20 ...

Over Thanksgiving weekend, I drove my 255,000 mile 1992 Jeep Cherokee 1,300 miles from Michigan to and from Virginia. It’s a vehicle whose engine I had blown up three years prior and swapped ...