Battle of the heavy weights

john&bet wrote:
Would have been nice to see the tach's of each truck during those runs. The max. rpm in the V-8's is much higher than the I-6, thus so is the max. hp, thus so is speed. I am not running anyone up a hill period. 18 wheelers with 80k running 20 mph maybe different, those trucks I will probably pass, but not with wide open throttle and second gear.

Actuaslly it doesn't quite work that linear.

Diesel burn is more a controlled burn and expansion of gases and less explosive than gasoline. Sooo the longer stroke diesel gives that fuel burn more time to extract horsepower from the burn while relatively short stroke V8's cut that off before all power BTU's can be extracted but making up for it by having more power pulses in the same time frame. Whew!

Torque being king while towing is the reason why the big honchos (classes 6-8) stuck with long stroke V8's and also why MOST large marine diesels have also stuck with the longer stroke engines.

That is not to say V8's don't have an edge during certain periods of the power cycle though and the more recent diesel designs are capitalizing on those to a degree never before seen.

The issue of auto transmission design along with heat dissipation from that auto transmission will now assume preemminence over what the engine is capable of. Making a transmission capable to use all of that power through a broader band AND getting rid of the resultant heat from that efficiency without transferring it back into coolant will be a test of engineer's 'outside the box' thinking skills.

All three of them are giving you choices that just a couple of decades ago would not have been believed possible. Whichever truck you choose, consider yourselves fortunate.