2050lbs of torque

Well over half the failures so far are on the Efficiency series for the X15. The most serious of which are the cases of liners rocking and/or dropping. The higher cylinder pressures and downsped spec of the Efficiency series are the cause. There are a handful of these cases in the Performance series, but it leans heavily to the Efficiency series. These newer Cummins engines do not need to pulled below 1200 rpm.

The fuel burn between a Performance 505/1850 and Efficiency 505/1850 in the same specs will be negligible. Within two tenths MPG.

 

So 1200 s/b ok?

 

Actually seems that most problems have been from the smaller egr cooler cracking, ingesting coolant, causing the bottom end issues... Just like the Volvo D16 experienced until they fixed the cooler design.... It's not that they aren't capable of handling downspeed RPM but that's the easy blame.

The fuel economy difference being darn near 1.0 mpg better with the X15e efficiency series vs X15p performance in aero trucks. Big difference, far more than .2 mpg. IDK some people don't care about fuel mileage very much though.

Either one I'd definitely get the warranty extended out to 500k , if it was the efficiency series I'd take advantage of the 600k warranty offering.

Either one, if it's rated with peak Tq below 1200 (1000rpm X15E & 1150rpm X15P), they absolutely do need to be able to be pulled to that RPM regularly in a working truck that doesn't live on flat ground.

 

Interesting discussion. As ignorant about this technical staff as I am, let me ask here. Should it not be the torque as an expression of an engine "might" rather than Horsepower? I understand the two correlate closely but since it is the torque what we feel when going up the hill or how fast we can build up speed on a flat road, is it not a little misunderstanding to talk about number of horses rather than foot pounds?

P.S.
Or please explain: If I can get the same peak torque from two different engines e.g. D13 455 hp or 500hp then why should I care about the latter having more horses?

 

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Torque without horsepower, is as useless as horsepower without torque. Thinking of it in its simplest terms, torque can best be described as doing work, and horsepower is the speed at which the work is done. Not exactly, but that is a close enough explanation. Big hp and torque numbers are what so many focus on, and after more than 3 decades of pulling very heavy loads, I've come to realize that its really just a super small aspect of the trucks I drive. Reliability, comfort, and the drivers control over the load means so much more than the engines power, which only matters when pulling a long steep hill. Lets say that you are actually using full throttle 10% of the time, and the power difference of the engines means that you climb a hill 10% slower that 10% of the time, you will only add 1% to your drive time.
Not a significant amount of time for most of us. A panicky few that worry about their speed, would be better served waking up 5 minutes earlier, or stopping for 1 less coffee, which also adds an extra pee break, wasting more time per day than a little less hp/torque adds to their drive time. By the way I pull 140,000 lb loads regularly with 475hp or 505 hp rated engines, in the extremely mountainous BC Canada. Low bedding with over weight permits, its nothing for me to gross out at 165k to 180k lbs. A mere 70k or 80k lb load for me feels like running half empty.

 

That's a great explanation ^^^.

I've always liked this one too: Horsepower is how hard you hit the wall, torque is how far you move the wall.

 

Torque is the lever, horse is amount of force applied to it, what I've always been told anyway.

 

I get it...longer lever renders more torque when applied by the same force (horsepower). Basic Physics says it is the force of turn/twist.. Thus it is possible to get the same torque with engines that have different horsepower or different torques with the same hp but different levers...but where's that lever in an engine?
Ok never mind...I need a drink anyway.

 

Correct. The might of a diesel is torque.

Torwue is the work performed, horsepower is how fast it's performed.
Either one skewed in out of balance ratios won't perform well.
Example;
500hp series 60 detroit, 1650lb-ft.
Notorious for not pulling very good, needs more rpm.

Compare this to a 500hp N14 Cummins with 1850 lb-ft and the Cummins wins every Hill.

In a Volvo, the top tier "XE" package uses 455hp w 1750lbft. I think the new ones are bumped to 1850 now.

Putting a 500/1750 vs 455/1750 on a hill and there is almost zero difference except the 500 burns more fuel.

I would take a 2050lbft motor with 450hp if they made it lol.

Really wish they had the X15E available in 2050Tq at that awesome 1000rpm peak tq.

In Summary;
You want the TQ# in a semi truck....the hp# has far less meaning.