Here in South Africa the first KJ to arrive was the 3.7 Gasser Automatic. I loved the look of it in all respects but the first published Test Drives by the local Auto mags reported the heavy fuel consumption....Gas (Petrol)...is very expensive here so I waited a while for the 2.5 L Export Diesel to come out and gave that a test drive.
At that time I was driving a Landrover Freelander 2.2 L Diesel....no power and useless off-road but pretty economical to run.
I straight away placed my order for the Diesel 5 speed Manual...took months for it to arrive while the price kept climbing due to our currency dropping against the Dollar!
Picked it up 11th May 2002 and still have it!
I only wish I had waited a few months more at which stage it came out with Disk Brakes at the rear and ABS as standard.
Reading all the KJ Jeep Forums over the years though I would say that the Diesel KJs have many more issues than the 3.7 Gassers so in the USA with low gas prices I would say that the 3.7 Gasser is a better choice!
The 2.4 L Gasser made a brief appearance here but its low power output soon saw its departure!