The Mercedes-Benz ML 320 CDI (W164 model, 2005-2011 generation) is a highly regarded vehicle, particularly in diesel form. Its benefits are best understood by looking at its core strengths: the engine, build quality, and overall capability.

Here is a detailed outline of its key benefits:

1. Engine & Powertrain (The Star of the Show)

  • OM642 V6 Diesel Engine: This 3.0-liter turbo diesel is legendary for its robustness, torque, and smoothness. It’s known as one of Mercedes’ best modern diesel engines.

  • Exceptional Torque: Delivers 510 Nm (376 lb-ft) of torque from just 1,600 RPM. This provides effortless pulling power, perfect for towing, overtaking, and relaxed highway cruising.

  • Strong Towing Capacity: Officially rated to tow up to 3,500 kg (braked), making it an excellent tow vehicle for caravans, boats, or trailers.

  • Good Fuel Economy for its Size: When driven sensibly, it can achieve around 25-30 mpg (US) or 9-10 L/100km, which is impressive for a heavy, powerful 4×4.

  • 7G-TRONIC Automatic Transmission: A smooth, responsive 7-speed automatic that complements the engine’s torque band perfectly.

2. Build Quality & Durability

  • Solid Bodyshell & Chassis: The W164 generation marked a significant step up in interior quality, material use, and structural solidity from the first ML.

  • Over-Engineered Feel: It delivers a classic Mercedes-Benz sense of safety and substantiality. The doors close with a solid „thud,“ and it feels built to last.

  • Corrosion Protection: Excellent rustproofing means body corrosion is less common than in many contemporaries.

3. Driving Experience & Comfort

  • Refined & Quiet Cabin: Excellent sound insulation, especially from wind and road noise. The diesel engine is well-muffled inside.

  • Comfortable Ride: The standard AIRMATIC air suspension (optional or standard on higher specs) provides a supremely smooth, wafting ride and allows you to adjust the ride height.

  • Confident & Stable on Highways: A superb long-distance cruiser, feeling planted and secure at high speeds.

  • Competent Off-Road Ability: With the 4MATIC permanent all-wheel-drive system, an optional Off-Road Pro Package (including a two-speed transfer case, center and rear diff locks, and enhanced underbody protection), it is a genuinely capable off-roader, far more so than most modern SUVs.

4. Practicality & Space

  • Spacious Interior: Comfortable seating for five adults, with a large, usable trunk.

  • Versatile Cargo Area: The rear seats fold nearly flat, and the split tailgate (a classic Merc SUV feature) is practical for loading or using as a seat.

  • Strong Residual Value: Well-maintained examples, especially with higher specs, have held their value reasonably well.

5. Safety & Technology (for its era)

  • Excellent Safety Credentials: Earned a 5-star Euro NCAP rating. Packed with safety features like multiple airbags, ESP, and a very rigid passenger cell.

  • Comprehensive Standard Equipment: Even base models came well-equipped with leather, power seats, dual-zone climate control, and COMAND infotainment (though now dated).

  • Advanced Options: Available features like DISTRONIC adaptive cruise control, Keyless-Go, and a panoramic sunroof were cutting-edge at the time.

Important Considerations & „The Flip Side“

To be balanced, potential buyers must be aware of known issues that, if addressed, protect these benefits:

  • Key Reliability Watch Points: The OM642 engine has some known failure points: swirl flap motor (in the intake), EGR valve/cooler issues, and potential for oil cooler seal leaks. A well-maintained example will have had these addressed.

  • AIRMATIC Suspension: Air struts and the compressor can fail with age (typically after 100k miles/10+ years), leading to expensive repairs. Check for a level ride and listen for constant compressor running.

  • AdBlue/Diesel Particulate Filter (DPF): This model does not have AdBlue, but does have a DPF. It requires regular long drives at highway speeds to regenerate and avoid clogging. Not ideal for constant short trips.

  • Maintenance Costs: Complex and requires specialist care. Cheap examples can be very expensive to fix. A full service history from a Mercedes specialist is a huge plus.

Summary & Target Buyer

The ML 320 CDI is an ideal choice for:

  • Someone needing a comfortable, torque-rich, and capable tow car.

  • A driver who covers high annual mileage on motorways/highways.

  • An enthusiast who values solid engineering, mechanical sophistication, and a feeling of durability over flashy modern tech.

  • A buyer who understands that preventative maintenance is key and who budgets for potential repairs on aging complex components.

In short, its core benefit is being a fantastically capable, robust, and comfortable long-distance workhorse that has aged well, provided it has been looked after properly. A pre-purchase inspection by a Mercedes specialist is highly recommended.