Low-Mileage M120 6.0 Liter V12 Engine (20,000 Miles) – Complete Drop-In with Updated Harness

Offered here is an exceptionally rare and highly desirable M120 6.0-liter V12 engine with only 20,000 documented miles.

The legendary Mercedes-Benz M120 represents one of the most advanced naturally aspirated V12 powerplants of the 1990s. Engineered by Mercedes-Benz, the M120 is renowned for its smooth power delivery, overbuilt construction, and immense tuning potential.

This example is complete, documented, and features an updated wiring harness, eliminating one of the common aging concerns associated with early M120 engines.

Technical Highlights

• 6.0-liter naturally aspirated V12

• 48 valves (DOHC configuration)

• Approximately 389–400+ horsepower (factory spec dependent on application)

• Massive torque output with effortless delivery

• Legendary smoothness and balance

The M120 powered flagship models such as:

• W140 S600

• R129 SL600

• C140 CL600

It also served as the foundation for high-performance AMG variants and exotic applications.

Condition & Value

This unit:

• Shows only 20,000 documented miles

• Comes complete and ready for installation

• Features updated engine wiring harness

• Has been properly preserved and maintained

Low-mileage M120 engines are becoming increasingly difficult to source, especially complete examples with documentation.

Perfect For

• W140 S600 restorations

• R129 SL600 builds

• C140 CL600 projects

• AMG 6.0 conversions

• Custom V12 swaps

• Investment-grade parts collectors

Whether restoring a flagship Mercedes or planning a high-end performance build, this engine represents a serious foundation.

Collector & Investment Appeal

The M120 is widely regarded as one of the last “overengineered” Mercedes V12s. As 1990s flagship models rise in collectibility, original low-mileage engines are becoming premium assets.

Reasons this engine stands out:

• Extremely low documented mileage

• Updated wiring harness (major reliability advantage)

• Complete configuration

• Increasing global demand for V12 powertrains

Naturally aspirated V12 engines from this era are no longer produced — making preserved examples increasingly valuable.