Why is Kenworth using Paccar if their reputation is so bad?

None, if you want an emissions legal truck, you buy a new truck with an emissions motor, not a Glider.

 

Uhh, it's not the drivetrain that has to comply with emissions, that would be the engine.

 

I own a 2014 pete 579 with a Paccar 500/1850.
I'd say the motor is great, it has the same emission system as the ISX, which has had the infamous DEF nozzle failure a few times. There is no power lag with the motor, any oil consumption at all, even though the engine intervals are suggested at every 40k miles. I'm amazed at how there's no oil "fallout" nor leak or either burnt.

The coolant is there, no leaks, nor problems with the EGR cooler, so the performance is top notch.
I've run loads of 8+ mpg, and others of up to 10 mpg with very light loads and feathering the throttle. My lowest mpg has been 6.4mpg and this calculations have been at the pump, though my gauge is not far of .5+/- mpg.

I would recommend this engine as I have no trouble with it, the design logic means it really is supposed to hold up to 1m miles before a rebuild, given the oil intervals with respective oil tests.

Even so all engines have a failure, maybe one day I'll come to learn of one in my own Paccar.

And I will agree to a Post before, ANY NEW EMISSIONS ENGINES' WORST ENEMY IS IDLING.

 

Thanks to everyone. Lots of intelligent, useful information. Learned a lot. It's really great that there are so many who take the time to help out. Really cool.

 

I'm wondering if they've changed a few things then.

Our paccar powered kw's are 2011 and 2012 models, and they are just gutless. one of them you have to downshift while going over a bridge even while empty.

I hope your engine lasts long, maybe the newer ones are better

 

I think the early motors were 1650 torque and like 450HP. A friend of mine bought a 2014 and loves it. He has had some sensor problems, but he found a dealer that is up to speed on those problems and has not lost any time due to being down. I think he said he was getting 7-9 MPG. He does watch his speed.

 

Yeah ours are 455/1650, 3.36 rears with one having 3.70s

 

I drove 110,000 miles in a 2014 Pete 587 with the paccar/10speed. Fairly decent power, but the fuel economy was outstanding. 1 engine related trip to the dealer at 65K for a software update, zero oil consumption, quiet. Now in a 2015 Volvo with the I-shift. The tranny is the cat's pajamas, I mean, it makes the truck. Waay better engine brake (tied to the cruise control if driver wishes). But the fuel economy is HORRIFIC. I'm at 5.4mpg, where with the paccar I was at 7.6mpg on the same routes, pulling the same tanks. Lower 48/Canada. On level ground across Nebraska or Saskatchewan, at 65mph, no wind, Volvo 6.4, Paccar 8.5. Same tires, rears, only diff is the pete ran 1250 rpm and the volvo runs 1075 rpm. If it were ME specing a new truck, it would be a T660 or T680 with a 500 Paccar in a heartbeat over anything else out there. Best of luck.

 

The Paccar is a strong motor. I truly believe that. The downside to a Paccar is that you can only get it worked on at KW or Pete dealers.

 

Joe, you're misunderstanding the 'B' numbers. If an engine has a B-50 number of 1,000,000 miles, then 50% of the motors would be expected to have needed a rebuild by that mileage. B-50 is also sometimes noted as MTBF (Mean Time Between Failure,) even though they don't technically mean the exact same thing. B-10, as you can deduce, means that 10% of motors are expected to have been overhauled by that mileage/time.

The B-50 gives a fair estimation of the life of an engine series, while B-10 can give insight into how many early failures can be expected. The further apart the two are, the more likely an engine is to be prone to premature failures.