Greg, putting a smaller engine in a vehicle will not necessarily give you better gas mileage. I have seen six cylinder engines in a pick up truck get just as bad or worse gas mileage than an identical one with an eight cylinder engine. Especially with a load on it. The same would happen by putting a four cylinder engine in a Cadillac. A smaller engine that is not designed for the car/truck and has to work too hard can get pretty bad gas mileage compared to a larger engine that can pull it easier. Have you ever noticed or heard about this?
