Anyone who tows in the Pacific Northwest knows the sinking feeling of watching engine temps climb as a mountain grade steepens. You pull out from the valley floor, hit a relentless 6% grade on Santiam Pass or Government Camp with an enclosed box trailer catching a headwind, and your truck drops three gears, screaming at 4,500 RPM just to hold 50 MPH.
We hooked a heavy tandem-axle Haulmark enclosed trailer to our black 2018 Ram 2500 Laramie Longhorn and pointed it west into the Cascades to see if fourth-generation Ram heavy-duty engineering still holds the crown for real-world Northwest hauling.
Quick Hauler Specs: 2018 Ram 2500 Crew Cab 4x4
Powertrain: 6.7L Cummins High-Output Turbo Diesel Inline-6
Output: 370 Horsepower / 800 lb-ft of Torque
Transmission: 68RFE 6-Speed Automatic with Tow/Haul Mode
Max Tow Rating: Upwards of 17,000+ lbs (configuration dependent)
Rear Suspension: Class-exclusive Five-Link Coil Rear Axle
The Sweet Spot of the Fourth-Gen (DS/DJ) Platform
Truck enthusiasts hold the late fourth-generation Rams in high regard for a reason. By 2018—the final chapter of this iconic body style—Ram had spent nearly a decade ironing out every quirk of the heavy-duty chassis.
You get the rugged, proven steel-frame bones that built Ram’s modern reputation, paired with modern tech like the 8.4-inch Uconnect system, Apple CarPlay, and factory integrated trailer brake controls. It represents that rare sweet spot: fully modernized convenience without the hyper-complicated, sensor-overloaded feel of newer platforms.
The Cummins Difference: 800 lb-ft of Pure Diesel Low-End
The true test came halfway up the mountain pass as the highway narrowed to two lanes and the grade pitched up. Under the hood, the legendary 6.7-liter Cummins inline-six turbo diesel barely broke a sweat.
Unlike high-revving V8s that need to hunt for redline to make power, the inline-six layout produces its wall of 800 lb-ft of torque right at 1,600 RPM. Leaning into the throttle to overtake a slow logging rig felt effortless; the boost spooled instantly, the 68RFE transmission held its gear, and the truck pulled the enclosed trailer uphill like it was running empty on a flat interstate.
Coming back down the other side of the pass is where most heavy hauls get white-knuckle. This is where Ram’s Smart Diesel Exhaust Brake changes everything. Tap the dash button, lift off the accelerator, and the variable-geometry turbo backpressures the engine. It holds the heavy trailer back with a deep, commercial-grade exhaust growl, saving your service brake pads from glazing over and keeping the steering wheel calm into tight downhill curves.
Taming the "Bucking Bronco": The Five-Link Coil Secret
Traditionally, heavy-duty three-quarter-ton pickups punish your spine with stiff, multi-leaf rear springs. Ram broke the mold for this generation by swapping out leaf springs for a heavy-duty five-link rear coil suspension.
On the road, the difference is immediate. When an empty enclosed trailer hits rhythmic concrete frost heaves on mountain bridges, standard leaf-spring trucks can hop and "buck." Ram’s coil-spring link design provides superior lateral axle control. It plants the rear tires, absorbs road chitter, and keeps the trailer tracking in a dead-straight line even when high-elevation wind gusts try to push you across the center stripe.
Ranch Luxury Inside the Longhorn
After hours behind the wheel wrestling mountain weather, stepping inside the Laramie Longhorn feels like walking into an exclusive high-desert lodge.
Ram didn't use cheap synthetic vinyl here. The Longhorn is wrapped in thick, saddle-grade cattleman leather with laser-etched Western filigree, paired with real burnished wood trim and deep-pile floor mats with removable carpet inserts. With heated and ventilated bucket seats, you stay cool climbing through sunny canyon flats and warm when the evening mountain air drops near freezing.
Ready to Hitch Up at Auto Kings
A truck like this isn't bought to sit in a suburban garage—it's built to pull cattle trailers, haul race cars, move heavy cargo boxes, and cross Cascade passes without flinching.
The exact 2018 Ram 2500 Laramie Longhorn featured in this run is thoroughly inspected, detailed, and available now on our showroom floor.
If you are looking for a proven, turnkey heavy-duty diesel hauler built to work across Central Oregon and beyond, stop by Auto Kings in Bend or Redmond to see it in person and hook up for your next big run.