Hunter Styres

00t444e

A 4bt Cummins would be a much better option than that 6.2 slug. It is smaller, easier to get power out of, and will get better mileage.

TRCM

google "4bt in a cherokee" or XJ.,..it's been done.

one of the issues you will have to deal with......it's a tall motor. look at the motor mounts in relation to the frame, and the oil pan in relation to the axle, and that's with a front leaf conversion.

cruiser54

Get another 4.0.

You'll NEVER recoup your money in fuel savings doing a swap like those above.

tinytrax78

The best bet would be Mercedes or vw if your set on diesel they are much lighter than both the 6.2 and the 4bt but if you are going for all out economy why not try a gas turbo engine like a ecoboost 4 or 6 cyl or maybe a gm 4.8 ls those run great and better on fuel than a 4.0 just kickin around ideas for ya

00t444e

The European diesels don't have nearly as much aftermarket as the 4bt does, and the 4bt is a better built engine.

tinytrax78

the 4bt is also way too big , way too heavy, cost way too much

Cummins93

A rebuilt 4.0L with properly operating sensors gets fairly good mileage. What is your mpg goal for gas vs diesel?

I had toyed with the idea of a few engine swaps but eventually went with a turbocharged 4.0L. For me it was a great option.

arto_wa

I think it would be better to buy used 4x4 that had Diesel already from the factory.
Grand Cherokee for example was available in North America with 3.0L Diesel 2007–2009.

4.3L XJ

Personally, I think those bread truck engines are way too noisy. It would drive me nuts. A turbocharged smaller diesel such as some of the VW and Audi diesels would work better. Some of them make some impressive torque. If you are looking for milage, look also at the Chevy LS series V8s. They get some very good milage too when geared properly with lots of get up and go when you want it.

arto_wa

I agree, however the AW4 electronic control would probably be a pretty big challenge and most likely he would need to have a manual transmission.

Photojared

This guy has a build thread either on here or NAXJA. He knows his stuff with TDI swaps. I'd love to go this route.
http://gastodiesel.tdconversions.com/