Whether you’re hauling equipment to a worksite, pulling a gooseneck loaded with valuable show horses or heading out on a cross-country RV adventure, confident towing depends on your diesel’s towing performance. Not all diesels are built the same — torque curves, cooling performance and longevity under sustained load can change how an engine feels on uphills, in heat and at highway speeds.
As the producer of leading, scientifically tested diesel additives that improve efficiency and performance, Hot Shot’s Secret can help you identify diesel trucks with the highest towing capacity. We break down engine types and key specs such as turbo design, gearing, torque and powerband, and reveal how to maintain and maximize performance.
Let’s turn up the torque and identify the best diesel trucks for heavy towing — and why they stand out.
What Makes a Great Diesel Engine for Towing?
Top diesel towing engines aren’t just about big horsepower numbers. They’re about how the whole powertrain delivers sustained muscle with a trailer hooked — torque, gearing, cooling and transmission logic all working together. Along with turbo performance and fueling strategy, each factor affects how the truck responds, how often it shifts and how efficiently it hauls loads mile after mile.
Some core towing performance traits include:
- High low-end torque: Strong twist at low rpm pulls heavy trailers from a dead stop and reduces strain on takeoff.
- Strong transmission pairing: Robust, properly matched gearboxes such as Allison or TorqShift handle high input torque and use smart shift logic to keep you pulling within the powerband.
- Durable internals: Sturdy components and designs rated for long service under load support engines during sustained climbs and high GVWR duty cycles.
- Effective cooling systems: High-capacity engine and transmission cooling systems prevent overheating and protect driveline components during extended and heavy towing.
- Turbocharger response and spool-up efficiency: Quick-spooling VGTs or well-matched turbos minimize lag, maintain performance at altitude and support strong midrange torque.
- Fuel economy under load: Efficient combustion and gearing that let the engine pull in its sweet spot reduce fuel usage, manage heat, extend range and reduce frequent regeneration cycles.
Under load and on grades, two engines with equal horsepower can perform differently. Torque is the differentiator — the twisting force that powers heavy loads from a stop. Diesel torque and towing go hand in hand. Low-rpm torque gets heavy trailers moving and holds speed on hills.
Top Diesel Engines for Towing: By Brand and Generation
Cummins vs. Duramax vs. Power Stroke towing — which one is best? Let’s take a closer look at diesel engines that consistently perform for towing by brand and generation. From proven workhorses to modern high-output 6.7L platforms, we focus on real-world delivery and maximum towing capacity. We call out standout strengths and common trade-offs like complex service needs so you can find the right setup for your trailer, routes and budget.
Headline specs vary by build, so always check a vehicle’s VIN to confirm its precise configuration and rated capacities.
6.7L Cummins: Ram 2500/3500
- Model years: Mid-2007 through 2025
- Torque/HP: Up to 1,075 lb-ft and around 420 hp in recent HO specs.
- Max towing capacity: Up to 37,090 lb gooseneck on Ram 3500 DRW HO with Aisin and 4.10 axle. The Ram 2500 max capacity is around 20,000 lbs with a standard-output Cummins.
- Strengths: Great for long-haul towing, the HO/Aisin combo handles torque well, making these engines known for durability and simplicity.
- Weaknesses: Higher upfront cost on HO/Aisin, and some early models had emissions issues.
6.7L Power Stroke: Ford Super Duty
- Model years: 2011 to 2025
- Torque/HP: Up to 1,200 lb-ft and 500 hp on 2023+ high-output engines.
- Max towing capacity: Up to 40,000 lb gooseneck on Ford 450 and 38,000 lb gooseneck on Ford 350. Max for conventional towing is up to 28,000 lbs in certain F‑350 trims.
- Strengths: Advanced towing tech and chassis with smart exhaust/engine braking and 10-speed TorqShift.
- Weaknesses: Complex emissions systems and higher service costs.
6.6L Duramax L5P: Chevy/GMC HD
- Model years: 2017 to 2025
- Torque/HP: Up to 975 lb-ft and 470 hp on 2024+ 6.6L Duramax L5P (Silverado/Sierra HD).
- Max towing capacity: Up to 36,000 lbs on 3500 HD dually and up to 22,430 lbs on 2500HD when properly equipped.
- Strengths: Quiet and durable with a responsive throttle and 10-speed Allison pairing that delivers smooth pulling.
- Weaknesses: Slightly less headline torque than Ford/Ram competitors in some years, and modern systems can raise maintenance complexity.
6.6L Duramax LBZ
- Model years: 2006 to 2007
- Torque/HP: Around 360 hp/650 lb-ft — verify exact figures by VIN.
- Max towing capacity: Mid-2000s 3500 dually models commonly rated around 16,000+lb fifth-wheel/gooseneck, depending on the configuration.
- Strengths: Legendary reliability, strong modding potential and pre-DPF/DEF simplicity reduce emissions failure points.
- Weaknesses: Older technology can affect safety and comfort. Watch for head gasket issues at high mileage and the lack of a factory lift pump.
5.9L Cummins: Common Rail
- Model years: 1989 to 2007
- Torque/HP: Up to around 325 hp/610 lb-ft in later years.
- Max towing capacity: Factory ratings for 2500/3500 in the 2000’s era commonly span roughly 12,000-16,000 lbs, depending on specs including axle ratio, cab/bed and 2WD vs. 4WD — always verify by the specific VIN.
- Strengths: Simple, reliable engines with strong low rpm, long life and high tunability. They are a great fit for budget builds and older platforms.
- Weaknesses: Older transmissions, suspensions and brakes vs. modern HDs, leading to age-related maintenance.
Towing Comparison Chart
| Engine | Max Torque | Towing Capacity | Emissions System | Ideal For |
| 6.7L Cummins | 1,075 lb-ft | 37,090 lb (3500 DRW) | Yes (modern SCR) | Long-haul towing, durability and simplicity. |
| 6.7L Power Stroke | 1,200 lb-ft | 40,000 lb gooseneck (F-450) | Yes (modern SCR/DPF/DEF) | Power and advanced towing technology. |
| 6.6L L5P Duramax | 975 lb-ft | 36,000 lb (configuration dependent) | Yes (modern SCR/DPF/DEF) | Balanced daily drivers and towers. |
| 6.6L LBZ Duramax | 650 lb-ft | Around 16,000 lb — verify per VIN | No DPF/DEF (has EGR) | Reliability and easy upgrades. |
| 5.9L Cummins | 610 lb-ft | Between 12,000 and 16,000 lb — verify per VIN | No (EGR usage varies by year/market) | Simplicity, durability, longevity and high tunability. |
Best Diesel Engines for Towing Fifth Wheels, Goosenecks and Trailers
The ideal choice for towing depends on matching the engine/transmission to your load and use case — heavy fifth-wheel and gooseneck rigs benefit from smart grade control and high-output platforms, while smooth, durable pairings are priorities for daily haulers.
Other important control and protection systems to note are:
- Integrated exhaust brakes for downhill control
- Trailer brake controllers
- Robust cooling systems to prevent heat soak on long trips and steep hills
Using these determining factors, our top picks for each trailer type are as follows:
- Fifth-wheel or gooseneck trailers: Look for a 6.7L Cummins or 6.7L Power Stroke.
- Construction or equipment haulers: Try a Duramax L5P with Allison pairing.
- Weekend warriors and occasional towers: Experience the value of an LBZ or 5.9L Cummins.
How to Keep Your Diesel Towing Strong for the Long Haul
Even the most reliable diesel engine for towing needs regular maintenance. Heavy towing stresses all parts of the engine and fuel system, so keeping them clean and clear optimizes performance and increases the lifespan of your investment.
Maintenance routines for towing vehicles should include:
- Oil changes with high-shear protection oils
- Fuel filter changes, plus fuel injector and turbo cleaning
- Diligent monitoring of EGTs, coolant and transmission temps while towing
Why Diesel Owners Trust Hot Shot’s Secret
Keep your towing truck in optimal condition with oil and fluid changes boosted with Hot Shot’s Secret additives. Our products are powered by science and are proven to reduce common engine problems and make your engine last longer — saving you on downtime and repairs.
Some useful products for towing vehicles include:
- Stiction Eliminator: Cleans and lubricates the oil side to reduce wear, which is vital for long-haul towing.
- Diesel Extreme: Restores injector spray pattern and improves fuel burn under load.
- Everyday Diesel Treatment: Adds power and protection to all diesels to improve fuel economy during towing and improve lubricity protecting CP4 pumps.
- Blue Diamond Oil: Improves wear protection and extended oil life for extreme-duty diesel towing and heavy loads.
- LX4 Lubricity Extreme: Protects fuel systems from ULSD wear — especially crucial under towing pressure.
Power Your Towing Rig With Hot Shot’s Secret
Give your engine what it needs to tow reliably up every grade and in all conditions. We are so confident you’ll feel the difference that we offer a money-back guarantee on every product. Truck owners nationwide trust Hot Shot’s Secret additives and oils to keep their towing vehicles hauling.
Contact us for customized product recommendations for your towing needs, or order your Hot Shot’s Secret power products now!