Detroit recently unveiled its new Gen 6 heavy-duty engine lineup, including the:
with production beginning in January 2027 for the DD13 and DD15, followed by the DD16 in January 2028.
Modern diesel engines are cleaner and more efficient than ever before, but they’ve also become far more dependent on electronics. Today, a relatively small component inside your Diesel Exhaust Fluid (DEF) system can take an otherwise healthy truck completely out of service.
One of the most common examples is the DEF header assembly.
If the DEF header fails—or if the Engine Control Module (ECM) receives inaccurate information from it—the truck may begin a series of emissions derates that reduce engine power and vehicle speed until repairs are made.
For fleets, owner-operators, and repair shops, that means lost productivity, missed deliveries, and unnecessary downtime.
That’s why Highway and Heavy Parts now offers DuraWRX™ DEF Management Solutions by Shaw Development—premium DEF headers and sensors engineered specifically for demanding commercial diesel applications and backed by an industry-leading 2-year warranty.
DuraWRX DEF Header Assembly by Shaw Development
Many people think the DEF tank simply stores fluid.
In reality, the DEF header is one of the most important components inside the entire Selective Catalytic Reduction (SCR) system.
A modern DEF header continuously monitors:
| DEF Level Measures how much fluid is in the tank. |
DEF Temperature Helps manage cold-weather operation and thawing. |
| DEF Quality Verifies proper fluid concentration. |
Heating Function Supports DEF flow during freezing conditions. |
| Fluid Pickup Draws DEF from the tank for system use. |
ECM Communication Sends critical data to the engine control system. |
The ECM depends on this information to determine whether the emissions system is functioning correctly.
If any of that information becomes inaccurate—or communication is lost—the ECM cannot verify emissions compliance. Instead of assuming everything is fine, it begins protecting the system by progressively limiting engine performance.
|
DEF Basics Learn what Diesel Exhaust Fluid does, how SCR systems use it, and what happens if DEF runs out. Read the DEF guide |
|
Sitting Too Long Learn how fuel degradation, DEF crystallization, moisture, and internal engine issues can show up after a truck sits. Read the diesel storage guide |
Unlike many engine failures, DEF system problems often have nothing to do with the mechanical health of the engine itself.
Your truck may continue running perfectly while a sensor begins reporting inaccurate information.
Eventually, the ECM responds by initiating an emissions derate.
This usually progresses through several stages:
| 1 Warning Light |
2 Fault Codes |
3 Engine Derate |
4 Reduced Speed |
5 Truck Down |
The actual replacement component may represent only a fraction of the repair cost. The real expense often comes from technician labor, missed deliveries, idle equipment, and lost revenue.
DEF components operate in one of the harshest environments on the truck.
They’re constantly exposed to:
Over time, these conditions can affect electrical connectors, heating elements, sensor calibration, seals, and internal electronics.
Some of the most common causes include:
Replacing the first component mentioned by a fault code isn’t always the right repair.
A proper diagnosis should include:
This approach helps prevent unnecessary parts replacement and repeat repairs.
Highway and Heavy Parts partners with Shaw Development, one of the industry’s leading manufacturers of DEF management systems, to provide premium aftermarket solutions for commercial diesel engines.
DuraWRX components are engineered to meet or exceed OE specifications while helping fleets reduce downtime and improve long-term reliability.
| OE-Style Fit Designed for straightforward replacement. |
Commercial-Duty Design Built for demanding diesel applications. |
| Sensor Accuracy Supports reliable DEF system readings. |
Corrosion Resistance Helps withstand moisture and road conditions. |
| Technical Support Backed by HHP application help. |
2-Year Warranty Provides added confidence in the repair. |
Highway and Heavy Parts offers a growing lineup of DuraWRX DEF management components, including:
Whether you’re repairing a single truck or maintaining an entire fleet, our ASE Certified Technicians can help verify the correct application before you order.
Modern emissions systems have become one of the leading causes of unexpected diesel truck downtime—but many repairs can be completed correctly the first time with proper diagnostics and quality replacement components.
Highway and Heavy Parts combines premium DuraWRX DEF management solutions with experienced ASE Certified Technical Support to help repair shops and fleet operators minimize downtime and restore dependable operation.
Call 844-304-7688 or visit highwayandheavyparts.com to find the right DuraWRX DEF components for your application.
From diagnosis through delivery, we’re Highway and Heavy Parts.
Vehicle emissions regulations did not happen all at once.
They developed over decades as engineers, regulators, and manufacturers responded to air quality problems caused by hydrocarbons, carbon monoxide, nitrogen oxides, particulate matter, and later greenhouse gas emissions.
For diesel engines, the biggest changes came when regulations began focusing more heavily on particulate matter, NOx, fuel sulfur levels, and aftertreatment systems.
Continue reading History of Vehicle Emissions Regulations: From Smog Controls to Modern Diesel StandardsHere at Highway & Heavy Parts, we sell a lot of turbochargers. We carry a number of the industry’s leading brands for all major OEMs, and have helped diagnose a lot of our customers’ turbo failures. We provide solutions to help get them back on the road.
Continue reading Highway & Heavy Parts Answers Your Diesel Engine Questions: TurbochargersAt HHP, we feel that our team of expert sales people is one of the things that really sets us apart from our competitors.
Continue reading Meet the Experts at HHP: Braeden GosmaAt Highway and Heavy Parts, we’re always working to improve how we support diesel repair shops and equipment owners. While our commitment to quality parts, fast shipping, and real technical support hasn’t changed, we’ve added new tools, products, and ways to stay connected.
Continue reading What’s New at Highway and Heavy PartsWe spend a lot of time talking about diesel engine parts – but today, we want to shift the focus to something just as important: the people behind it all.
If you’ve ever called in, asked a question, or needed help finding the right part, chances are you’ve already experienced what makes our team different. This is your chance to get to know one of those people a little better.
Continue reading Meet the Experts at HHP: Andy ThompsonModern trucking depends on more than just the truck itself.
Mobile applications now play a critical role in:
👉 The right trucking apps help reduce downtime, improve efficiency, and support safer decision-making on the road.
Below is a breakdown of widely used trucking apps in 2026, organized by function.
Continue reading Best Apps for Truck Drivers in 2026 (Navigation, Fuel, Weather & More)These are some of the most in-demand diesel engine components in 2026.
Each product below is selected based on:
Most diesel technicians assume a brand-new cylinder liner comes out of the box perfectly round and ready to install.
However, advanced dimensional analysis shows that even new production liners contain small amounts of geometric variation throughout the liner surface.
While these variations are often microscopic, they can still influence:
That is exactly what Highway and Heavy Parts explores in Black Series Lab– Episode 1. In this episode, we examine:
Most engine rebuild conversations focus on the parts everyone can see.
Pistons. Rings. Bearings. Cylinder heads. Gaskets. Liners.
But one of the most important surfaces in the entire engine is almost invisible once the rebuild is complete.
The cylinder liner crosshatch.
That microscopic pattern machined into the cylinder wall plays a major role in oil retention, piston ring seating, compression control, blow-by prevention, and long-term engine durability.
In Black Series Lab Episode 3, we look closer at that surface and explain why the liner wall is not just a smooth bore. It is an engineered sealing surface.
Some diesel engine problems only appear when the engine is working hard. A truck may:
…but suddenly lose power while:
This happens because high-load conditions place maximum demand on:
Under light driving conditions, weak components can sometimes “hide.” However, when engine demand increases, those weaknesses often become obvious very quickly.
Continue reading Diesel Problems That Only Show Up Under High Load
