Paccar MX opinions.

I gonna try to tell you what is the difference with DAF UPEC engine... They provide SMART injection system, it is like PLD pump (you can see on DAF, MACK and Mercedes engines), but injector is open not with pressure like in classical PLD system but with electric pulse like on common rail.
The good thing that when CRD injector fails and leaks in return line all rail pressure (ore rail section pressure) goes low and engine stalls, Paccar MX systel lets you limp home with missfiring engine.
So this system is more reliable, people say better then ISX HPI system ore Injector unit system.

mechanically engine is good like previous DAF engine.

Electronics is made by Bosch in cooperation with Delfi. Unit is good, may be damaged with overvoltage ore wrong battery polarity. To diassembly it is very difficult so usually we have to change them with new ore used.

For US market they do not install immodilizers so no lost keys problems.

Wiring is thin so if you drive on bad roads and engine runs wrong ore stalls check wiring first... may be one ore more broken wires....

Low end torque is limited with electronics so engine seems to be gutless till you reve it up to 1200 rpm, but thats why shift in time and it saves fuel!

 

Stay far away from these engines, personally I owned two older Paccar engined DAFs , first one needed to be rebuilt at 230,000 kms the second 540,000 kms , people I know are also having problems with newer engines, they also have a nasty habit of blowing to bits, deisel consumption is ok so is the power but I think they're built from butter or another soft substance, in a nutshell they're crap, 600,000 kms is about their service life, I never heard of one makin the 1 m mark without having work done,