Paccar MX or Cummins ISX

That's not what B10 and B50 is.

Both engines will have a B10 and B50 ratio - those are the typical measurement of miles and/or hours before 10 and 50 percent of those engines require a major repair, overhaul, or replacement.

PACCAR claims a 1 million mile B10 design life for the MX-13, and I think this is where you're getting confused. Where you're somewhat on the mark is that sellers tend to claim a 1 million mile B50 rating for the Cummins engine. However, PACCAR's B10 claim is at this point unverified - they simply haven't been on this market long enough to populate a reputable stat to support that claim, and the 1 million mile B50 stat from Cummins doesn't actually come from Cummins - it comes from various sellers, who claim a B50 stat anywhere from 1kk to 1.5kk.

It's certainly an intriguing claim, and I'm interested to see how it pans out, as well as what the B50 ratio for the MX will turn out to be, but let's not push an unverified claim as gospel, especially when what you're preaching is inaccurately represented.

 

I have 490,000 miles on my MX13 500hp engine, truck is a 2012 (motor is dated 2011)

Power is impressive and the only issue so far is emissions related crap and one belt tensioner, fuel economy is what I would expect from a 500hp engine that is loaded to 80,000 pounds 85 percent of the time it is running.

The cooling schematic is the best I have ever driven in 35 years, you simply cannot overheat this motor even in 120 degree weather pulling long grades with the A/C going full blast; amazing design.

I will say the concern over options for service is very real, pete and kw dealers are terrible and they are the only option if need work done and you cannot repair motors yourself; parts are also INSANELY expensive for the PACCAR MX engines.

We used to joke about how CAT charged 3 times as much as Cummins for the same components but PACCAR is out of this stratosphere for even the most basic components like air compressors and water pumps; beware if you are buying used and will be the owner when these bolt on components reach there life cycle.

My assessment is that the Paccar is a great engine being sold by a manufacturer that is only concerned with fleecing their customers after they purchase it.

For this reason I won't buy another but it's a shame, if they would loosen the strings on their service manuals and software so good mechanics could learn them and service them I would stick with them forever; but after fighting to get every shred of technical data I need to self maintain these engines I am going to switch to Cummins even though I think they make a slightly inferior engine.

 

The new KW's & Pete's with a PACCAR are about $12,000 less than an X15.

 

Yep, Paccar knows they will get that 12 grand back many times over once they have you shackled to their service department with that MX engine.

 

They have a fleet of 50 of them where I park my truck, and have nothing but good to say about them. No isues really.

 

Other than resale value don't expect godliness out of Cummins other than sorry we sold ya a pos and it's overhaul time around 750k.

 

You having problems with yours? Thought it was doing you good?

 

cummins all the way but your going to pay more for the truck, most mx trucks go for 10-15k cheaper

 

The service information and diagnostic software is available to anyone that wants to purchase it. No different than any other engine manufaturer in North America. I will admit there are hoops to jump through and people usually give up. Plus it's nowhere near as cost effective for single units or small fleets. Everyone always feels the access to this should be free for some reason.

 

Had an oil consumption problem that I have got straightened out Dave ...I just meant in comparison to pre emission engines are junk and if mine goes to a million before an overhaul I will have it bronzed lol