1/2/2017 · The ¾-ton and 1-ton Dodge Rams they grace can be made to produce 500 rwhp with relative ease, rack up more than 20 mpg on the highway and easily last more than a half a million miles. In addition to being the power plant of choice in the truck pulling game, the 12-valve is a regular choice in the engine swap world as well, powering countless Jeep, rat rod, muscle car and dragster projects.