Night And Day Difference: Comparing Old-School Diesel Workhorses With Today’s Mountain-Moving Monsters
In the world of diesel pickup trucks, this is the golden age—especially if you’ve got a lot of work to do. The compression-ignition equipped ¾-ton and larger trucks leaving Detroit today are more powerful, efficient and capable than they’ve ever been. But exactly how have towing and payload ratings bulged as high as 40,000 pounds and 7,000 pounds, respectively? While it might appear that diesel trucks leapt from 15,000-pound tow ratings to 40,000 pounds in the blink of an eye, the reality is that a slow, steady progression of improvements gradually made higher and higher capacities possible.
Along the way, key frame, suspension, axle, drive line and hitch changes have occurred—all of them geared toward making these North American workhorses live up to their “heavy-duty” nomenclature. Throw in diesel engines that turn out four-digit torque numbers at very low rpm, diesel-specific transmissions with tow-friendly operation and shift strategies, and you get the modern-day, unstoppable behemoths being built by Ford, GM and Ram. This time, we’re covering the major advancements implemented by The Big Three over the past 20 years to get us to this point: “light-duty” trucks putting up medium-duty numbers.
Then Vs. Now
Things change, right? Well, in the world of diesel pickup trucks things have changed exponentially in terms of towing and payload ratings since rigs like the one pictured ruled the road. Back in 1997, this single rear wheel F-350 boasted a maximum tow rating of 13,400 pounds (fifth-wheel). In 2023, the same configuration truck (albeit a Super Duty) can lug as much as 23,500 pounds (fifth-wheel). Compare a ’97 dual rear wheel F-350 with a ’23 version of the same configuration and the disparity between the two grows considerably: 13,800 pounds vs. 35,800 pounds.
Difference #1: More Powerful Engines
Perhaps the most noticeable difference in the diesel trucks of yesteryear and those being produced today exists in the power ratings. Twenty-five years ago, the 7.3L power Stroke V-8 in Ford’s new (at the time) Super Duty kicked out 235 hp and 500 lb-ft of torque. Today, Ford’s high output 6.7L Power Stroke (right) turns out 500 hp and 1,200 lb-ft. A similar story can be written about how far the Cummins in Ram trucks (and even the Duramax in GM trucks) has come in that timeframe. The Cummins option that powers Ram trucks has grown from 235 hp and 460 lb-ft in 1999 to 420 hp and 1,075 lb-ft at the present time.
Ever-Advancing Fuel & Turbo Technology
Paving the way for the aforementioned horsepower and torque increases were significant advancements in diesel engine technology. The electronically controlled, high-pressure common rail injection systems of today are far superior to the electronic-over-mechanical and HEUI arrangements that were used at the turn of the century. Common-rail enjoys a much-improved ability to precisely meter fuel, clean up emissions and produce more power. Variable geometry turbocharging also proved a game-changer in terms of getting heavy loads up and moving quicker. And not only can VGT technology be used to accelerate 40,000 pounds of rolling mass quickly, but it can also be used in the form of a turbo brake to help bring everything to a quicker halt.
Efficient, Intelligent Transmissions
Allowing more powerful engines to seamlessly motivate the vehicles they’re bolted to also boils down to great transmissions. Equipped with full electronic control, quick learn capability and advanced diagnostics, today’s diesel-specific automatic transmissions are about as high-tech as they come. They also benefit from well-engineered and highly efficient lockup style torque converters, not to mention the Tow/Haul modes they feature offer exceptionally refined, tow-friendly shift strategies. The 10-speed versions available from Ford and GM (the 10R140 TorqShift and 10L1000 Allison, respectively) also have the ability to perpetually keep the engine in the meat of its torque curve.
To cope with ever-increasing towing and payload ratings, The Big Three have revised their trucks’ foundations over the years. Today’s truck frames are stronger and thicker than they’ve ever been. Long gone are the days of C-channel frame rails, modern diesel trucks feature fully boxed frames—not to mention an increased amount of cross members for added (and needed) lateral rigidity. Looking at Ram’s heavy-duty truck frame for example, it's made of fully boxed, “resilient high-strength steel” with specific sections made of 63,000-psi high-strength steel.
For improved handling and stability, it stands to reason that the Detroit Three have also upgraded their suspension systems in recent times. Higher spring rates on leaf springs and coil springs, wider leaf springs, larger torsion bars and control arms (GM), and improved shock absorbers have all been implemented. GM even added assymetrical rear leaf springs beginning in ’11, which substantially helped to quell axle wrap in its Duramax-powered HD trucks. Ram introduced its Auto-Level rear air ride system in 2013 (shown), which provided automatic load-leveling capability.
Beefier Axles & Drive Line Parts
Paralleling what was done to the frames and suspension systems in order to handle heavier loads, driveline technology has also improved. Most notably, these items (axles, driveshafts, U-joints, etc.) have gotten bigger. The biggest rear axle available in a 2000 model year Ram 2500 or 3500 was the full-float Dana 80, a venerable unit with a 11.25-inch diameter ring gear. When Ram’s heavy-duty trucks were revamped in 2019, a full-float AAM rear axle with a massive, 12-inch ring gear was added, along with axle tubes measuring a stout 4.250-inches. The latter trucks also came with larger, 142mm hubs and an 8x200mm lug pattern.
The last (but arguably most important) piece of the mountain-moving puzzle lies in hitch selection. In order to live up to all the 30,000, 35,000 and 40,000-pound towing hype, commercial-grade, factory-optionable hitches had to be available. Ford’s top-tier gooseneck hitch kit is rated for 40,000 pounds (via 3-inch ball). Of course, there are aftermarket options, which come in handy when a truck has only been “prepped” for a fifth-wheel or gooseneck from the factory but didn’t leave its dealership equipped with the hitch itself.
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