Hi Guys, I just helped my son-inlaw buy a 1999 Ford Ranger Ex-Cab. It's got a 4.0L V6. The truck is in excellent condition with a 84K mile 4.0L V6 that runs well, but, it gets terrible gas mileage. Is there something to be done about it with fixes to the 4.0L motor or would it be better to swap in a 4 cylinder motor? If 4 cylinder motor, can you recommend things I need to watch out for?