I think somewhere there has to be a balance...between cubic capacity....HP/torque being produced...purpose of the HP/torque.....general durability and long term longevity of certain high stress components. In this case the...high rpm, bearing cooling, capacity of the turbocharger(s).I towed 10,000 lbs over 700 miles this weekend and the only time my rpm went higher than 2300 rpm was while entering the freeway. It rolls 65 mph at 1800 rpm, rarely coming out of OD. This helps on engine longevity. Transmission I'm not so sure.
