Jeep 4.0L Engine Specsby Justin Cupler
Jeep's 4.0-liter, inline-six engine was quite legendary. Not only did it provide outstanding power relative to other engines in its class in the early years, but it also delivered outstanding reliability -- save for some common oil leaks -- and its production ran from 1987 through the 2006 model year. The only 2006 Jeep model to still use this venerable engine was the Wrangler.
Jeep 4.0-Liter Engine Specs
The 4.0-liter engine had 12 overhead valves, and a 3.88-inch bore and 3.41-inch stroke, resulting in an 8.8-to-1 compression ratio. It produced 190 horsepower at 4,600 rpm and 235 foot-pounds of torque at 3,200 rpm. In the Wrangler, with the six-speed manual transmission mated to it, this engine earned mileage ratings of 13 mpg city, 17 mpg highway and 15 mpg combined. With the auto transmission, the ratings dropped to 13 mpg city, 16 mpg highway and 14 mpg combined.
- Justin Sullivan/Getty Images News/Getty Images