It used to be that "locking the hubs" was a fundamental first step when heading off-highway. Over the years though, OE manufacturers defected from the lockout hub. Most four-wheel-drive vehicles built ...

The last time around, we added a larger, slightly heavier wheel and tire combo and lost a little more than 1 mpg. Granted, with the 6.7L's whacked-out emissions system that dumps raw fuel into the ...