Family boats with the inboard motor are almost always well-appointed with a sterndrive powertrain, which combines an automotive-type machine mounted inside the ship with a steerable and trimmable drive unit mounted on the stern of the boat. The exception is for a dedicated watersports towboat with an inboard engine turning a propeller under the ship, with routing control provided by a rudder.
Outboards are accessible from tiny 2-horsepower kickers to 600 horsepower, but for family boating range is usually 90 to 300 horsepower. A new outboard motors engine has become more powerful, gaining popularity on larger cabin cruisers and day boats that equipped it with inboard engines. You may feel rigged with three or four outboards that combined create more power than a giant pair of sterndrive engines presented, resulting in performance that was when unimaginable.
Inboard Vs. Outboard Motors Pros And Cons
Initial Cost Comparison
It looks natural to make a cost comparison on horsepower—a 250-horsepower outboard motor to a 250-horsepower sterndrive in the same boat—but it is wiser to compare it based on performance.
In this case, a 200-horsepower outboard motor will usually match the performance of a 250-horsepower sterndrive as the outboard weighs less since that weight is more efficiently positioned behind, rather than inside, the boat. The rule of thumb holds when you move up and down the horsepower scale. However, with less horsepower, the outboard-powered boat can often cost a little more—2 to 4 percent—than a similar boat size with a sterndrive.
Inboard Vs. Outboard Engine Maintenance Costs And Ownership
Because it usually weighs less and has a more efficient design, an outboard motor typically delivers better fuel economy. Both will need similar annual maintenance, except that in cold weather, the cooling system of most sterndrive engines wants to be flushed with antifreeze solution, generally by a marine service center.
An outboard is self-draining, and several owners can accomplish their off-season service.
Sterndrives had a reputation for being more prone to corrosion-related problems in saltwater. Still, corrosion resistance is much better-quality on modern engines and outdrives, and many are well-equipped with a closed cooling system that has most saltwater out of the machine.
However, you cannot tilt most sterndrives entirely out of the water, though most outboards can clear the water when slanted up. It is an advantage for the new outboard motors engine if the boat is getting docked or moored all the time in saltwater, as it avoids marine growth and corrosion from arising on the drive.
As the entire engine is outside the boat, an outboard motor is more accessible to service than an inboard engine. With the ship on a trailer, you can stand next to the outboard.
Checking the inboard requires working under an engine hatch is pretty cramped confines. When an outboard is facing damage or worn out, it is relatively easy to re-power the boat with a new outboard engine. Repowering an inboard boat is an option but a more challenging project.