DEF going away ?

[Shawn T. W.]

But "my lane" is actually in the industry as a tier one supplier, closely partnered with the OEMs producing internal combustion engines for the CTOHI industry. My employer manufactures a wide variety of engine components, sells to nearly every engine manufacturer, and I manage our engine dynamometer lab to test all of it. So I am deeply integrated within the industry that relies on and sells this emissions compliance technology in all of their engines/vehicles.

I can tell you this: none of the OEMs are talking about warranty concerns, problematic DPF/SCR systems, or anything like that. There were a lot of teething problems 10 years ago, sure. But the broad industry perception is that this is a solved issue.

Maybe you should try a brand new truck instead of driving all those old beaters with early emissions compliance systems.

I'm not bashful and will share my experience with pictures ...

I'm not @Hay Dude , but I drive what most here would consider a "brand new" truck .. or at least it was when our company representative picked it up at the Kenworth plant in Chillicothe, OH, and drove it to our headquarters to get processed into our fleet ... I picked it up at 327 miles on the odometer this spring on May 2, 2025 ... Here it is just today ... A 2026 T680 with a Cummins X15.

This picture is also just taken ... The check engine light is on for the second time! While is probably "only a $100 sensor" it means down time for me, time I can't be taking care of a customer, plus the shop time ...

Here are the stickers in the door jamb ...

And the engine ...

And the transmission can certainly effect the engine!

I have the PACCAR 12 speed automatic transmission (worst thing I've ever driven in over 33 years of driving a truck!!!)

Between the programming of the engine and the transmission it doesn't really allow the engine to "work" in my opinion, it double shifts (skip shifting ) and lugs the engine down ... You can see where this redlines, and at the governed speed of 68 mph, it's just barely over 1200 RPM ... It's just lollygagging along, diesels, especially modern emissions diesels need to work hard to run efficiently, so for all the money they "save" in so called fuel economy, I generally get "mid 8's" ... They more than make up for it extra maintenance and headaches expenditures!

This is not an old beater, by any standard, although I hate driving it! But it is a strangled, compromised truck!!!

 

[EscapedSuburbia]

I can tell you this: none of the OEMs are talking about warranty concerns, problematic DPF/SCR systems, or anything like that. There were a lot of teething problems 10 years ago, sure. But the broad industry perception is that this is a solved issue.

I have no experience in the heavy truck world but do in the diesel pusher RV world and the DEF failures have definitely not been solved. Improved, but not solved. DEF head failures are still a very common complaint in new RVs.

 

[Hay Dude]

I don’t think much anyone’s buyin what deezler’s sellin

 

[dnw64]

I don’t think much anyone’s buyin what deezler’s sellin

Some people are their own best customer.

 

[deezler]

Lol. I appreciate the anecdotal pieces of evidence.

Was just trying to share the perception from the engineering side...

The engines are all robust, at this point. The Cummins X15 hasn't changed much in years - It does just fine loping along at 1200rpm low load, indefinitely. The challenge comes when you need to integrate a comprehensive exhaust aftertreatment system onto it.

For what its worth, I feel like I am noticing a pattern with Paccar and DPF/DEF/SCR issues. The aftertreatment system isn't always engineered or integrated by the engine manufacturer (which is dumb).

 

[deezler]

I'm not bashful and will share my experience with pictures ...

I'm not @Hay Dude , but I drive what most here would consider a "brand new" truck .. or at least it was when our company representative picked it up at the Kenworth plant in Chillicothe, OH, and drove it to our headquarters to get processed into our fleet ... I picked it up at 327 miles on the odometer this spring on May 2, 2025 ... Here it is just today ... A 2026 T680 with a Cummins X15.

This picture is also just taken ... The check engine light is on for the second time! While is probably "only a $100 sensor" it means down time for me, time I can't be taking care of a customer, plus the shop time ...

View attachment 4562188

And the transmission can certainly effect the engine!

I have the PACCAR 12 speed automatic transmission (worst thing I've ever driven in over 33 years of driving a truck!!!)

Between the programming of the engine and the transmission it doesn't really allow the engine to "work" in my opinion, it double shifts (skip shifting ) and lugs the engine down ... You can see where this redlines, and at the governed speed of 68 mph, it's just barely over 1200 RPM ... It's just lollygagging along, diesels, especially modern emissions diesels need to work hard to run efficiently, so for all the money they "save" in so called fuel economy, I generally get "mid 8's" ... They more than make up for it extra maintenance and headaches expenditures!

This is not an old beater, by any standard, although I hate driving it! But it is a strangled, compromised truck!!!

Just because I am curious, and to clarify....

You say "2nd time" the CEL is on, at 94k miles? Thats not particularly awful, is it? What is the CEL actually for? No reason to bash the aftertreatment system that is keeping our air clean if you don't even know what the CEL is on for. Your dash lists and error in the lane departure system....

And yes, the transmission affects the engine, but my point was that a having transmission faults, error codes or mechanical issues does not imply that it is wrong or even at all associated to have a DPF and SCR system in the exhaust keeping our air clean.