2025 Mercury Marine® 4.5L 250hp ECT Base

2025 Mercury Marine® 4.5L 250hp ECT

Featuring a host of engineering innovations, the 4.5L series establishes new standards for power-to-weight ratio, driver experience, acceleration, durability, and ease of maintenance.

Features may include:

• The Mercury Marine 4.5L 200hp sterndrive is a 2015 Boating Industry Top Product of the year.

• The winning products were selected based on many factors, including innovation, impact on the industry, and how they advanced their category or created a new category.

• Designing a V-6 block solely for marine use allows Mercury to build the 4.5L with the ultimate protection system, using cast-iron componentry where the engine intersects with seawater, and using corrosion-resistant aluminum and composites everywhere else.

• Thanks to its new, long-runner scroll intake manifold which draws in more air and converts it into additional torque, the 4.5L delivers a ground-breaking power-to-weight ratio and gives you V-8 power in a V-6 package.

• The 4.5L’s newly designed rear-facing throttle body, anti-whistle throttle plate, engine cover and mounts, lightweight flywheel, fuel-supply module, and structural oil pan all work together to deliver a superior idle, smoothness and low vibration. Resulting in an exceptional driving experience.

• The MercFusion Paint System creates an outer seal against the elements, while MerCathode® provides automatic protection against galvanic corrosion. For maximum defense against saltwater effects, the SeaCore® industrial hardcoat anodizing system and closed-cooling circuit is available.

• The 4.5L comes standard with Adaptive Speed Control, which automatically maintains engine rpm regardless of load or water conditions. The result is increased throttle response and a sporty feel.