In today's logging industry cost savings takes over riding priority, yes the series 60 is different in the sense that the torque is gained on the bottom end of the RPM ratio. More importantly fuel savings is huge. When a company is taking on a trucker, whether it be fuel provided or fuel supplied, the cost can make or break the deal. I have dealt with one series 60 and numerous Cummins ISX's and can say that the difference between mechanical and electronic engines is what gives truckers the leading edge in today's market. Gone are the days of naming your price. Competitive is the tomorrow we work in. Furthermore, to drive a 4 stroke engine opposed to a classic 2 stroke is like taking a stock vehicle and adding nitrous.