When we talk about jeeps or 4x4s, then fuel consumption should be put aside. Because everyone knows that Jeeps are not fuel efficient. They are made for tougher rides and difficult paths, they have to pull load, have to roll massive tires and what not. Hence fuel efficiency factor doesn’t exist here.
Even if we take world’s most fuel efficient engine, fix it in 5-door jeep and expect that it should give us 15km/l average and also should pull the load of 5 people on board with their mountain size luggage bags, tents and food stuff too. Then it never gonna work.
Engine like 5VZ, 1UZ, 1GR, 1HZ, 1HD, 1KZ, 1KD, etc. are made for jeeps where they have good repute to handle off-road stuffs.