the great thing about the powerstoke is how it does going down the road. i have had all the diesels and pulled with them WAY overloaded. the cummins was the best at gettin the load movin as the peak torque is at a lower RPM, but it lost its power on the highway and in the hills as cruising speed had the motor running above its useful torque curve. the PSD will be slower at gettin the load movin but does better on the highway and doesnt loose as much in the hills as cruising speed is still in its designed torque curve. the duramaxs are inbetween the cummins and the PSD, got the load movin faster than the PSD but not as fast as the cummins, lost pulling power on the highway more than the PSD but not as bad as the cummins. now dont get me wrong the PSD will not pull 50k lbs up a mountin at 100mph... but on the highway pulling the psd cant be beat for pulling power and fuel effeciently. some may disagree but these are my expericnces from pulling with different trucks all over the country. and this is also comparing stock trucks
Read this. This is an absolutely EXCELLENT bit of information. Great stuff.
If you do some research on the PSD's, primarily the 6.9 IDI, 7.3 IDI, and 7.3 PSD, you'll find that when International designed these motors, they were almost exclusively making tractor motors, and "IN LINE" motors at that. And EVERYBODY questioned International as to WHY, they designed the motor the way they did. Why they used an opposed cylincer motor, and not an in line motor? Well, WRIOTT's description, explains perfectly, "WHY" International designed the motor the way they did.
The idea was to try and blend capabilities. Yes, the in line motors are torquier, and they get the load moving easier, but they fall off on the top end. Opposed motors take a little more to get a load moving, but will perform much better at cruising speeds. Well, the folks at International recognized the fact that people were towing longer and longer distances, and they were towing at greater and greater speeds. This little bit of insight, led them to design the PSD.
Great info, and great insight and comparison Wriott, thanks.