Mercury Marine Outboard vs. MerCruiser Sterndrive Engines

When members of the PartsVu community interested in Mercury Marine engines ask us which type of engine is best, we generally recommend that they first find the boat that fits their needs and the kinds of activities they like to do. The boat comes first, and in almost every case, the best power source will become apparent. This said, there are a lot of options, and it can become a bit overwhelming.

Boaters have four basic options for powering a boat:

• Outboard engines
• Sterndrive, inboard-outboard, or IO (all names for the same engine type)
• Jet drive engines
• True inboard or v-drive engines

This article focuses on the pros and cons of the choice most Mercury boaters face. Is a Mercury Marine outboard or a MerCruiser sterndrive powered boat better? The answer to this question, of course, depends.

Like all outboard engines, a Mercury outboard is a complete powertrain bolted to the back of the boat. So what are the pros and what are the cons?

Mercury Marine Outboard Pros

• Outboard power is more compact and does not take up space inside the boat giving you more seating and storage capacity.
• Outboard engines are usually lighter weight, offering a higher power to weight ratio.
• Very reliable
• Easier to work on and, generally speaking, better for owners doing much of their own maintenance
• Easier to maintain in saltwater environments. In saltwater environments, gravity is an important ally helping to drain the water and preventing saltwater from sitting on the engine, contributing to costly corrosion.
• Lower maintenance costs reducing the overall cost of ownership
• Outboard owners often extend their boating season a bit because there is not a lot of freeze damage risk.
• When an outboard engine is completely trimmed up, you can access shallow waters.
• Because the engine lighter, it typically creates smaller wakes
• Offers flexibility, particularly for larger or performance vessels, as multiple Mercury outboards can be assembled to deliver desired power.

Mercury Marine Outboard Cons

• Older outboards are louder; however, this is not necessarily true for newer models.
• Older engines tend to be less fuel-efficient
• Takes up significant space on the swim platform
• Blocks access entering the water from the back of the boat.
• Can be stolen more easily
• Typically has less torque.

Typical Applications of Mercury Marine Outboards

• Pontoon boats
• Aluminum fishing boats
• Bass boats
• Smaller day boats
• High-performance offshore fishing boats
• Deck boats
• Becoming increasingly popular in the bowrider market
• Small cruisers, particularly in saltwater

MerCruiser Sterndrive or Inboard-Outboard Engines (IOs)

A MerCruiser sterndrive is essentially a car or truck style engine mounted inside the boat, lower in the hull. The engine is then connected through the transom, or back of the boat, to an outdrive unit that hangs down below the boat's bottom.

MerCruiser Sterndrive Pros

• Better handling in very rough water due to its deeper draft
• Has a more car-like feel because the engine is more like a car/truck
• Can be quieter
• Can be more fuel-efficient
• Offers an unobstructed swim platform at the back of the boat

MerCruiser Sterndrive Cons

• Takes up space inside the boat
• More expensive to winterize and maintain
• Not as easy for DIY maintenance
• Engines are heavier, so the power to weight ratio is typically a bit less than an outboard.
• It is not possible to completely trim the drive unit up out of the water, making shallow water access difficult.

Typical Applications of Mercury Sterndrives

• Bowriders
• Midsize to larger cruisers
• Freshwater applications more common

While it’s not PartVu’s style to make recommendations relating to which engine technology to buy, we can tell you that the marine industry is moving decidedly toward outboard power. While this article largely addresses those loyal to or interested in Mercury Marine power solutions, Volvo’s acquisition is telling.

Long known for its diesel- and gasoline-powered sterndrives, inboards and pods, Volvo Penta has been well known and respected for a long time for its diesel- and gasoline-powered sterndrives, inboards and pods. In 2017 Volvo bought high-performance outboard manufacturer Seven Marine, which builds 557-hp and 627-hp outboards based on a General Motors LS V-8 block.

Outboards have become increasingly powerful, efficient and new technology is being developed to support them. As just one example, for Mercury outboards, their Joystick Piloting for Outboards offers amazing maneuverability and control.

Boaters and boat manufacturers alike have become much more comfortable powering luxury and performance boats with multiple, high-horsepower outboard engines. For those who have been active in the boating world for a long time, it might be a little strange to think about multiple high-horsepower outboards hanging off of these high-end boats. But, multiple engines offer both reliability and flexibility.

There can be a lot of noise in the boating world relating to the types of available engines. Ultimately, it can be a little overwhelming. But, we hope you found this article helpful as you explore your options. Make sure you get the right Mercruiser parts for your boat to always have the best engine performance.