I'm still trying to figure out why 1/2 ton trucks need to have diesels. You won't save that much weight over just buying a 3/4 ton. So yeah the 1/2 ton with a V8 cummins might get a few miles per gallon better than the gas V8's, maybe even better than a real Cummins. But the lighter weight truck will be almost as heavy, and every bit as expensive. And when the new owners of those trucks decide that they need to tow with them, the smaller drivetrain will be the weak point. I know that there are V8 diesels out there with lots of miles on them. But I've gotta say I kinda like the saying "6 in a row make 'em go" Not to mention I have seen people just downright abuse inline six diesels and they just keep kickin'