I am Seriously considering going back to Cummins but is there really any difference anymore. On of my buddy's is having good luck with the new Peterbilt engine but it's only 13.0 liters ?
All of our "standard" trucks (only pull 80,000 lbs) has had the 13 liter ISX for several years. Decent power and mileage. We have more problems with the emmisions and UltraShift transmissions than anything.
I've looked at some reports for the last few years and the Detroit is the least expensive for maintenance for the first 900,000 miles.