Photos courtesy Mercury Marine

In a nod to securing their future and providing the company with the ability to better meet market demands, Mercury Marine has developed an all-new V6 engine for sterndrive applications, the MerCruiser 4.5L. The new 4.5L series provides a solid power-to-weight ratio, pumping out 250 horsepower at a maximum rpm hovering between 4,800-5,200.

The engine offers a number of notable features engineered specifically for marine use, unlike past engines that have been used in this type of application.

Electronic fuel injection is standard on the pushrod two-valve-per-cylinder engine, which has cast-iron parts where the engine intersects with seawater to better resist corrosion. Aluminum and composites that resist corrosion are used everywhere else.

The company put a heavy focus on torque to provide a better boating experience, developing a new long-runner scroll intake manifold for this application.

Newly designed parts include the rear-racing throttle body, an anti-whistle throttle plate, new engine cover and engine mounts, a lightweight flywheel, and a structural oil pan. All of these components are designed to provide an engine that runs smoothly with low vibration to provide a better user experience.

Adaptive speed control is also standard, which maintains engine rpm no matter what the load and water conditions are, providing better throttle response.

The engine uses a 4.000-inch bore and 3.600-inch stroke and runs on regular 87 octane pump fuel.

They also focused on providing easy maintenance options for owners – there is a front-mounted drive lube monitor and color-coded maintenance points. The company has also produced a number of how-to videos; these are easily accessible through QR codes that can be scanned with a smartphone.