I had a mid 90s Cherokee. It was a rugged little beast but terrible gas mileage for the size. Not nearly as good as typical full size pickups.
Not sure what it is that causes Jeep vehicles to get such bad mileage. I was amazed that a car with so little power could get such bad mileage. When it was almost new, my Wrangler wit he V6 engine got at best 14 MPG on the highway if I drove very conservatively. I was probably getting 12-13 MPG highway with it when I sold it. My F-150 gets about 19 MPG on the highway, and even on my work commute I am getting about 16-17 MPG consistently. The only downside is it’s significantly more challenging to park.