Volvo vs. MerCruiser vs. Ilmor Sterndrive Boat Motors (Pros & Cons)

Are you having trouble deciding between brands for the best sterndrive motor for your new boat? If so, stick around because this article will explore and compare three top brands: Volvo, MerCruiser, and Ilmor.

But maybe your newfound passion is still at the beginning stages, and you are still unsure what type of boat is most suitable for your needs. I know that any significant investment can sometimes be stressful, especially when there is more at stake than just its economic impact on your budget.

The good news is that your conscience is in the right place. You want to be sure that the boat and motor you choose are both durable and versatile- no matter if you plan on putting it through the most rugged exploring and fishing scenarios, lean towards watersports, or prefer leisure and entertainment.

What Is A Sterndrive Motor?

What Is A Sterndrive Motor

Often called an inboard/outboard motor, sterndrive marine engines are one of three main propulsion configurations for boats. The design of the sterndrive motor captures the most significant advantages of both the inboard and outboard motor.

More specifically, it takes standard inboard motors’ power and torque capabilities and combines them with the driving response and improved maneuverability of outboards.

Typically, inboard motors sit towards the middle of a boat’s hull; however, boat owners mount their outboard motors on its transom, keeping the engine and drive system entirely outside the boat.

Sterndrive motors are four-stroke engines housed within a locker mounted at the boat’s stern just inside the transom. These motors have an extended steering shaft propelled by gears that extend through the bottom of the transom with its propeller aligned, similar to an outboard motor.

Advantages of Sterndrive Motors

  • An Unobstructed Stern- can be advantageous for you if easy access in and out of the boat is essential. In addition, this is a worthwhile consideration if you plan on using your boat for watersports. And, lastly, you have the option to install a rear deck since you do not have any motors in the way.
  • More Storage Capacity- Inboard motors set at the center of a boat’s hull immediately bite a chunk out of your storage capacity and limits your boat’s configuration options. Since sterndrive motors mount at the boat’s stern, you have more freedom to reconfigure your boat’s deck arrangement, even adding additional storage.
  • A Quieter Ride- can be achieved by utilizing specifically formatted soundproof material inside the engine bay. This feature may be exciting to those boat owners who do not like noise or refuse to speak above the engine while entertaining guests.
  • Aesthetic Appeal- though outboard motors are pretty sleek looking and tend to give an edgy appearance to the stern of one’s boat, many boat owners prefer not seeing their engines. With the location of a sterndrive at the boat’s stern and enclosed within a locker, there is almost no visual evidence of a motor onboard.
  • Great Wake- A sterndrive motor is a much safer option for those at the rope behind your boat for watersports. In addition, sterndrive motors are known for pushing out great wake, or the waves it creates by displacing water behind the boat. And for watersports enthusiasts, wake is foundational for a great ride.
  • Maintenance By far, outboard motors are the most DIY-friendly motors to perform routine maintenance on. On the contrary, inboard motors are perhaps the most difficult to access its various components. Since both inboard and sterndrive motors are most similar to automobile engines that contain several intricate parts, some mechanical skill is a definite requirement for working on these engines.
  • Fuel Efficiency- You will have to master some finesse to maintain speed with a sterndrive motor. However, when put to the test against an inboard engine, the boat with the sterndrive motor will go faster. In addition, sterndrive engines can be up to 20% more fuel-efficient than inboards, and with today’s outrageous fuel prices, that sounds pretty good to me.
  • Directional Reverse- When placed in reverse, a sterndrive motor enables the captain to move in any direction desired, similar to outboard motors. In contrast, an inboard engine can only move straight back at reverse thrust.
  • Stability- Sterndrives provide boaters with a smooth and comfortable ride. And because this motor sits at the boat’s stern, this lower center of gravity improves the handling and stability of the boat.
  • Parts Availability- If you decide on popular sterndrive motor brands such as Volvo or Mercruiser, replacement parts are usually readily available, so hopefully, you should not have to endure too much downtime.

Disadvantages Of Sterndrive Motors

  • Prone to Corrosion- This argument becomes based on whether you mind performing a little more involved boat maintenance. Inboard motors do not have any direct contact with the water, so it is less prone to any of the corrosive effects of saltwater environments. In addition, outboard motors have a tilt function that can lift the entire engine out of the water for storage, trolling, or other periods of extended downtime, therefore giving the boat owner the ability to reduce its exposure to saltwater and marine growth. But sterndrive motors are sort of stuck in the middle- with specific components constantly exposed to either the saltwater or brackish water underneath.
  • Winterization- In addition to performing more detailed maintenance, winterizing a sterndrive motor is more complicated than an outboard. Depending on your location, your boating season may be greatly limited since you cannot expose these motors to freezing conditions. In any case, most boat owners hire a professional marine mechanic to winterize their boats.
  • Cost- Hands down, an outboard motor is usually way less expensive than an inboard or sterndrive motor. The fact of the matter is, marine development of the outboard engine has reached the point where it can outperform and outprice most of the competition while maintaining the highest EPA standards. In addition to up-front costs, you should consider long-term maintenance costs. And because it has more moving parts than a typical two-stage outboard, sterndrive motor maintenance costs are higher.

What To Look For In Sterndrive Boat Motors?

What To Look For In Sterndrive Boat Motors

If you have already decided that a sterndrive motor is the most suitable option for your boating needs, it will help you know what you should be looking for when comparing different brands.

Boat owners should ask themselves some reasonably common-sense questions when considering the purchase of a boat motor. As you look at influential sterndrive motor brands, please consider the following:

  1. What is the intended purpose of my boat? Fishing, exploring, leisure and entertainment, or watersports.
  2. How big is my boat? The size and specific engine ratings should coincide with your boat’s overall length.
  3. How many people do I plan on carrying? Whether you use your boat for fishing, summer parties, light/heavy-duty transport, etc., you should know how many people and how much total weight you plan to carry.
  4. Is my boat-to-motor combination fuel efficient? Unless you have loads of money to give to the fuel industry, having the most fuel-efficient configuration should be highly important, primarily if you use your boat frequently.
  5. How expensive is it to maintain and repair the engine? Long-term costs are always a consideration when making a significant investment, so you want to be sure that you don’t end up with a boat sitting around for months on end because you just don’t have the money to fix it.
  6. What type of warranties are offered by the engine manufacturer? If you have just spent years of your hard-earned savings or have taken out a personal loan to purchase the boat and motor of your dreams, the security of having an industry-leading warranty is enough to give anyone the warm and fuzzy’s and good night sleep.

What Brand Sterndrive Boat Motor is Right For Me?

Sterndrive boat motors have been around for just shy of a century; however, the modern design of today’s leading brands must give thanks to Charlie Strang- a visionary MIT engineering student that “wanted to beat the outboard speed record.”

As we have seen throughout this article, a symbiotic relationship must exist between weight and power to produce a happy boat and thus a satisfied boat owner.

Although outboard motors have been taking great strides within the marine motor industry and lead in terms of eco-friendliness, fuel efficiency, and lightweight, you will be happy to learn that sterndrive motor manufacturers are hard at work to close the gap.

When selecting either a Volvo, Mercruiser, or Ilmor sterndrive motor, you should always keep your list of boating preferences in mind. As we discuss each motor brand, you will notice specific features each company values the most.

Volvo Penta Sterndrive Boat Motor

Volvo Penta Sterndrive Boat Motor

Since its debut, Volvo has stayed focused on marinizing automobile engines. The process of marinization includes adding, changing, or deleting specific parts to make the engine marine-worthy.

Volvo’s Aquamatic sterndrive motor first hit the market in 1959 and is still a top favorite of boatowners seeking both high and mid-level power output and response.

The Aquamatic sterndrive is available in both gasoline and diesel configurations, including both inline models and the V-shape technology designed by General Motors.

Their latest most impressive innovation is their Forward-Drive sterndrive motor which flips the script 180 degrees. This motor pulls the boat through the water by forward-facing counter-rotating propellers, guaranteeing comfort and performance.

Volvo sterndrive motors are committed to excellence and should be a top contender for the engine that will propel you and your family’s boat this next boating season and for years to come.

MerCruiser Sterndrive Boat Motor

MerCruiser Sterndrive Boat Motor

Instead of marinizing automobile motors, Mercury has dedicated itself to building marine-grade sterndrive motors from the ground up. MerCruiser offers an impressive line-up of sterndrive motors and four different drive options based upon your intended use.

The Alpha One drive system is both high performance and fuel conscious, making it a leader in the boating industry. With a line-up that can offer the boating enthusiast up to 430 horsepower, the MerCruiser sterndrive motor is a classy beast on the water.

If you intend to be clocking plenty of nautical saltwater miles, then you can select MerCruiser’s “SeaCoreĀ® industrial hardcoat anodizing system and closed-cooling circuit” for maximum defense against corrosion.

Ilmor Sterndrive Boat Motor

Ilmor Sterndrive Boat Motor

We sometimes tend to think that heritage equals quality. But please don’t turn your head at the fact that Ilmor’s Marine Division was born not long ago in 2004.

I think that the company’s warranty speaks for itself. Why else would they offer a 5-year/500-hour factory-backed guarantee unless they meant business?

Ilmor sterndrive motors are incredibly concerned about providing customers with a highly corrosion-resistant sterndrive motor so that customers will not be stuck with replacing costly parts due to damage caused by either saltwater or brackish water.

Even though their marine division may be young, I forgot to mention that Ilmor has plenty of experience in the automotive racing industry. From over 35 years of building its name and reputation in big-league racing events such as the all-American Indy 500 and the international Formula One Championships, let’s just say they decided to lend a hand to the marine boating sector.

Depending on the model of the sterndrive motor, you can select between their One-Drive or One-Touch Joystick drive system. The acclaimed Joystick provides an impeccable response on twin-engine boats; however, the electromagnetic clutch of the One-Drive system delivers smoothness like never imagined.

With many parts made on American soil and plenty of service centers nationwide, Ilmor’s sterndrive motors fit the bill for any recreational or power-seeking boat enthusiast.


The design of sterndrive motors will power your boat while maintaining outstanding ratings for power, response, fuel efficiency, and comfort. In addition, the technology behind its configuration makes for a highly durable product that can handle the rugged conditions of any marine environment.

In particular, Volvo, MerCruiser, and Ilmor sterndrive boat motors are renowned for providing high-performance satisfaction to customers around the world.

So, as you begin shopping for a suitable sterndrive motor for your boat, remember to search for a solution that fits the primary use of your vessel.

If you need further assistance deciding between a Volvo, MerCruiser, or Ilmor sterndrive boat motor, do not hesitate to contact an authorized dealer in your location, the manufacturer, or feel free to leave your questions and concerns in the comment section below.

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