Mercury 170 TIER 3 172.4 HP 2.0L Inboard Diesel Engine: Full Review, Specs, and Applications

In the world of marine propulsion systems, Mercury Marine has established itself as a pioneering leader, especially known for its reliable and innovative outboard and inboard engines. One of the standout products in its diesel engine lineup is the Mercury 170 TIER 3 172.4 HP 2.0L Inboard Diesel Engine. Engineered for durability, efficiency, and superior power delivery, this compact diesel inboard engine meets stringent emission regulations and is tailored for a range of commercial and recreational marine applications.

Whether you’re a boat builder, fleet operator, or recreational user, understanding what this engine offers can help you make an informed choice. This article explores everything about the Mercury 170 TIER 3 — from performance and specifications to environmental compliance and common use cases.

Overview of the Mercury 170 TIER 3 Diesel Engine

The Mercury 170 TIER 3 is a 2.0-liter, 4-cylinder, common-rail direct injection diesel engine. With an output of 172.4 HP at 4000 RPM, this model is ideal for small to medium-sized vessels, including patrol boats, rescue crafts, fishing boats, and yachts.

Mercury designed this engine to provide high torque at low RPMs, which results in excellent acceleration, fuel efficiency, and load-carrying capacity. It’s TIER 3 compliant, meeting EPA Tier 3 and EU Stage IIIA marine emission standards, making it an environmentally conscious choice.

Key Specifications

Performance and Efficiency

The Mercury 170 TIER 3 is built for consistent performance in various marine environments. Thanks to its advanced turbocharging system and intercooler, the engine maintains optimum combustion temperatures, enhancing power delivery and efficiency.

High Torque Output

This engine generates 350 Nm of torque at just 2000 RPM, allowing vessels to plane quickly, even when fully loaded. The high torque ensures a smooth cruising experience, minimal engine strain, and lower maintenance needs.

Fuel Economy

The engine’s common rail fuel injection system helps deliver fuel at high pressure directly into each cylinder, resulting in precise fuel atomization. This technology improves combustion efficiency, reduces fuel consumption, and cuts down on carbon emissions.

Quiet and Smooth Operation

The Mercury 170 is notably quieter than older diesel models due to its balanced crankshaft design, noise-absorbing engine mounts, and advanced ECU tuning. Vibration is minimized, offering a smooth experience even at high speeds.