|
So are you solely looking at engine options that would fit in your existing Jeep? What MPG are you getting now and what tires/transmission to you have now? What MPG would you like to achieve?
My expedition type off-roading vehicles have evolved from a 1991K2500LD with 350 NV4500 NP241 3.73 on 255/85R16s to a 2005 Toyota Tacoma with 2.7L R155F 4.10 4x4 on 235/85R16. Mild (<2”) height adjustments on both, with several other mods for MPG/off-roading on both. I got maximums of 18MPG highway with the first rig, and 28 MPG highway with the second rig. Both were very capable offroad for moderate trails. My next high MPG on/off road vehicle is going to be based around a 90’s model GMC Diesel Suburban, 6.5 NV4500 NP241 3.42 rest TBD.
I wouldn’t be so quick to dismiss aerodynamics for expedition style off-roading (which I think is what you meant by your title, ignore this if it wasn't). When I think of expedition style offroading, I think of plenty of driving on paved backroads between stretches of light to moderate offroading. The idea is more of sightseeing and going places than running trails in a dedicated rig.
This totally wouldn’t be that practical and I don’t know about $250 at self-service yards, but given your basic requirements I would find a 2ZZ-GE from a Celica/Corolla/Matrix and figure out how to adapt it to one of the Toyota R15X transmissions which should be doable. For four wheel drive then pair that to a stock whatever transfer case was available behind the R- series transmission that works, preferably one with aftermarket 4.xx:1 low range gear sets available which is almost as good as a doubler. The 5 speed in some jeeps is an AX-15 which is the same thing as a Toyota R, General Motors AR-5 , Jeep AX-15, NV3550, and Isuzu AR5, all the same family of Aisin transmissions with minor differences. Gear it low and don’t be afraid of RPMs as the 2ZZ likes to spin, but has fairly high BSFC so MPG should still be good. (For gearing reference the factory 2zz transaxle came with 4.56 final drive gears in a car with 24" tires turning out in the 30s for MPG.)
Once again, I wouldn't suggest actually doing what I just suggested above, I would rather suggest re-looking at your starting vehicle and perhaps find a capable offroader that would put out more MPG stock (like a 1999-2000 4Runner with 2.7l, 5 speed, 4x4).
|