2025 Ram HD Refresh: Unified Diesel Engine, New Tech, and Major Transmission Upgrade
The 2025 Ram HD Refresh: A Unified Diesel, Bigger Screens, and Real Towing Gains
The 2025 Ram 2500 and 3500 are getting their first major refresh in several years, and while some details remain official-only in Ram’s hands, the mechanical and technology upgrades are substantial enough to matter if you’re in the market for a heavy-duty truck. The changes break down into three major areas: engine strategy, transmission, and infotainment.
The Diesel Engine Story: Consolidation, Not Cancellation
One rumor that’s been circulating is that Ram is dropping its diesel option for the 2500 and 3500. That’s not quite right. Instead, Ram is consolidating its diesel lineup under a single, significantly upgraded 6.7-liter Cummins inline-six turbo diesel.
The new Cummins produces 430 horsepower and 1,075 pound-feet of torque—a meaningful jump from the previous generation. That torque figure is what catches attention: it’s best-in-class for heavy-duty trucks, and the low-end peak torque means better real-world pulling feel at highway speeds and under load.
Ram redesigned the engine block and cylinder head, upgraded the pistons, added a more aggressive intake manifold, and fitted a new turbocharger with a higher-pressure fuel system. One notable durability change: the older grid heater has been replaced with conventional glow plugs, which should improve cold-start reliability.
The block material itself changed from compacted graphite iron (CGI) back to traditional gray iron. On paper, that might sound like a step backward, but Ram’s reasoning is practical: gray iron reduces engine noise and vibration, which matters when you’re spending 40+ hours a year in the cab.
Eight Speeds Instead of Six: The Transmission Upgrade
The 2025 Ram HD trucks jump from an aging 6-speed Aisin automatic to a newer 8-speed transmission. The extra gears allow the engine to operate more efficiently on the highway—fewer RPMs at cruise means less fuel burned and less engine wear over the life of the truck.
Combined with a new 3.42 rear axle ratio (optimized for the new engine’s torque curve), the 2500 and 3500 claim 36,610 pounds of maximum towing capacity with the diesel engine. For context, that’s a meaningful number if you’re towing heavy fifth wheels or gooseneck trailers regularly.
Technology Trickling Up from the 1500
The 1500 refresh brought some significant tech updates to Ram’s truck lineup, and several features are now available on the 2500 and 3500 heavy-duty models.
The headline is the 14.5-inch Uconnect 5 touchscreen, which debuts on the 2500/3500 heavy-duty trucks. That’s the largest truck infotainment screen in production, and it comes paired with Ram’s new Atlantis electrical architecture—a backend upgrade that makes the system respond five times faster than the previous generation, with response times as quick as 0.05 seconds. Wireless Apple CarPlay and Android Auto are standard, along with built-in navigation and Wi-Fi hotspot capability.
The passenger display is also new to the heavy-duty lineup: an optional 10.25-inch interactive screen on the passenger side lets riders access entertainment or navigation without distracting the driver. Dual wireless charging pads are available too, so both driver and passenger can top up phones simultaneously.
The infotainment updates aren’t just about size—they’re about workflow. Ram’s interface has historically been straightforward, and the new system maintains that while adding redundancy (multiple ways to access climate, navigation, and media controls) that makes it easier to find what you need while driving.
The Hemi V8 Stays
Ram’s 6.4-liter Hemi V8 continues as the gasoline option for 2500 and 3500 models, producing 405 horsepower and 429 pound-feet of torque. For buyers who prefer gas—simpler servicing, no DEF fluid, no glow plugs—the Hemi remains a solid choice, especially if your towing needs are moderate.
What This Means If You’re Shopping
If you’ve been on the fence about buying a heavy-duty truck, the 2025 refresh gives you real reasons to wait rather than snag a 2024 closeout. The diesel upgrade alone—more torque, improved reliability features, faster transmission—addresses complaints that have dogged Ram’s heavy-duty line for years. The tech additions aren’t luxury fluff; they’re practical improvements (larger screens, faster responsiveness, wireless charging) that make the truck more usable for work and daily driving.
The trade-off is price: Ram’s consolidation of the diesel lineup and these upgrades won’t come cheap. But if you’re a heavy diesel user, the 1,075 lb-ft torque figure and the new transmission pairing are worth comparing against Ford and Chevy’s current heavy-duty offerings.