1994 3.0 caravan SE

I just dropped in another motor with 25K on it from a 1996 Caravan(my Caravan has 170K on it). And I have to say that the only MPG difference with this other engine is that in town mileage is a little better. I get about 18-20 in town and about 22-24 highway. This is just running straight unleaded...no super or premium. And I also use NOTHING but Pennzoil 10W30 if anyone is curious.