Which Ram 2500 Engine is the Best?

Oct 16, 2024

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When choosing a heavy-duty truck like the Ram 2500, the engine you select determines far more than just horsepower. It affects towing, payload, fuel economy, maintenance costs, and even resale value. Ram offers multiple engine options to meet the wide range of needs—from commercial hauling to weekend recreation. But the real question is: Which Ram 2500 engine is the best?

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Let’s break it down with a detailed comparison and expert-level insights into performance, specs, use cases, and ownership factors.

Overview: Ram 2500 Engine Options for 2025

As of the latest model year, the 2025 Ram 2500 offers the following engines:

Engine	Type	Horsepower	Torque	Max Towing	Fuel System
6.4L HEMI V8	Gasoline	410 hp @ 5,600 rpm	429 lb-ft @ 4,000 rpm	17,730 lbs	Sequential multi-port
6.7L Cummins Turbo Diesel I6	Diesel	370 hp @ 2,800 rpm	850 lb-ft @ 1,700 rpm	19,990 lbs	High-pressure common rail
6.7L Cummins High Output (3500 only)	Diesel	400+ hp	1,075+ lb-ft	37,000+ lbs	(2500 Not applicable)

Note: The high-output Cummins engine is exclusive to the Ram 3500 and not available on the 2500.

Engine #1: 6.4L HEMI V8 – The Best for Gas-Powered Utility

✅ Pros:

Best-in-class gasoline towing (up to 17,730 lbs)
Standard engine in most 2500 trims (Big Horn, Power Wagon)
Delivers responsive performance at higher RPMs
Paired with the 8-speed automatic, offering smoother gear shifts
Lower upfront cost than diesel

❌ Cons:

Less torque at low RPMs compared to diesel
Lower fuel economy, especially under heavy load
Louder engine note when under stress

Who It’s Best For:

Weekend haulers
RV owners
General contractors who prefer lower maintenance costs

Real-World Use:

The 6.4L HEMI offers excellent acceleration, especially off the line. When paired with 4.10 axle gearing, it’s a strong performer for hauling medium-duty trailers and payloads without the diesel price premium.

Engine #2: 6.7L Cummins Turbo Diesel I6 – The Torque King

✅ Pros:

Massive low-end torque (850 lb-ft @ just 1,700 rpm)
Ideal for towing heavy loads and long-distance hauling
Proven reliability with a legendary Cummins nameplate
Better fuel economy than the 6.4L under full load
6-speed Aisin automatic transmission handles torque smoothly

❌ Cons:

More expensive upfront and higher maintenance costs
DEF (Diesel Exhaust Fluid) system requires upkeep
Heavier engine affects front axle weight and payload capacity
Slight turbo lag at low speeds

Who It’s Best For:

Long-distance haulers
Commercial operators
Towing 5th wheels, horse trailers, or equipment

Real-World Use:

If you’re regularly towing more than 10,000 lbs, the Cummins diesel pays for itself. With fewer revs needed to achieve maximum torque, the engine stays cooler and more efficient under stress.

Gas vs Diesel: Which One Should You Choose?

Factor	6.4L HEMI V8	6.7L Cummins Diesel
Towing Capacity	Up to 17,730 lbs	Up to 19,990 lbs
Payload	Slightly higher	Slightly lower (due to engine weight)
Fuel Economy	Worse under load	Better under load
Upfront Cost	~$9,000 less	More expensive
Maintenance	Lower	Higher (oil, filters, DEF)
Longevity	150K–200K mi typical	300K+ mi with maintenance
Transmission	8-speed auto	6-speed HD automatic (Aisin)
Engine Braking	Less effective	More effective (diesel exhaust brake)

Cost of Ownership Comparison (Estimated Over 5 Years)

Category	6.4L HEMI V8	6.7L Cummins Diesel
Initial MSRP (Big Horn)	$61,000 CAD	$70,000 CAD
Annual Fuel Cost	$4,500	$3,700
Oil Changes (per year)	$150 x 2	$250 x 2
DEF Refills	N/A	$200/year
Repairs & Maintenance	$1,200	$2,000
Resale Value	Moderate	High

Note: Prices vary by usage, region (like California vs Alberta), and load demands.

Reliability & Durability

The 6.4L HEMI is known for its simplicity and lower long-term repair costs. It’s ideal for drivers who don’t plan on keeping the truck beyond 150,000 miles.
The 6.7L Cummins, by contrast, is a workhorse. Known for million-mile durability in the right conditions, it’s built for longevity but comes with higher parts and service prices.