DD15 455HP vs DD15 560HP

I agree with you. If I would have 40k lb average load in my trailer I would buy big hp engine. My average load is about 20k lb and 455 hp is perfectly enough for me. Big engine means more heat is passing through DPF and there is less need of regeneration. Less regen means less problems )))

 

if truck has DEF tank its EPA10. If no DEF -EPA07

 

I should clarify this a bit more. If you are hauling flat interstates, then the smaller h.p./torque ratings can get you better fuel mileage. I'm just so used to pulling hills and getting better mileage with big power, I sometimes forget there are some that only haul light on flat highways.

 

My 2012 Coronado has the ACTUAL 560hp/1800lbs.tq. DD15 w/RTLO18913A tranny, 13.5k steer and 40k drives. 3.42 rears.

There's some misleading info here. HP= speed, quicker and that's it. If you wanna pull a heavy load or maintain speed/gear while pulling a hill or grade? That's all torque.

I think there is a typo in one of those truck specs. You don't see a 560/1600 spec. Somewhere around 475hp the torque spec shifts to 1800.

You plan on running reefer. Okay, where?

 

Did you buy one?

 

Unless one is pretty much pegging the tach, they are not ever going to reach peak HP anyway. If one is running a DD15 at 1800 RPM, they are already on the back side of torque and it is dropping like a rock. A 455HP 1750 lb torque DD15, for instance, at 1800 RPM where peak HP is, torque has already dropped to around 1300 lb. It started dropping off at 1500 RPM.

I am not convinced that a lower hp / torque motor is all that much more fuel efficient than a higher one. Even on flat ground. The motor is only going to drink the amount of fuel it needs to produce the power than is needed to move something. Whether it is a 430 HP or a 560 HP, if it only takes 200 hp to move the load, both engines are going to use the same amount of fuel to generate 200 hp. But on a hill, the higher powered motor could complete the hill faster and theoretically use less fuel overall. One has to look at gallon per hour ratios and times on the pull. Something many of us are not equipped to effectively measure and compare. So, I vote for more power. Better to have and not need than to need and not have.

 

You are right TheLittleGuy. I only used the h.p. numbers because that's how people know the models.
What I meant was my 505 is 1650 torque, and our 600 is the 1850 version.
I'm getting better fuel mileage in the hills with the 1850 torque.