Before getting into Mercury Marine’s new 350- and 400-hp V-10 platform, can we have a moment of silence for the 2.6-liter supercharged I-6 Verado platform, which will be retired from the lineup in 2023?
Nearly two decades ago, the I-6 Verado was unveiled at Hawks Cay in the Florida Keys, where I remember thinking, This could be the end of Merc. It just seemed like too much technology to be in such a harsh environment, and too small of a block to generate 275 hp. The last time I was that wrong was in 1990, when I thought boo.com was a solid investment. Not only did the I-6 Verado platform go on to great success, it was still going strong and cranking out up to 400 hp at the end of 2022.
With the introduction of the new 5.7-liter, V-10 platform, Mercury Marine has revamped its lineup of 175-plus-hp outboards in just four years. The lineup now includes V-6, V-8, V-10 and V-12 configurations that crank out up to 600 hp with nary a supercharger in sight. (Mercury Racing still makes supercharged outboards.) The strategy bucks the trend of slow, measured product development in favor of a wholesale changeover.
Tim Reid, Mercury’s vice president of product development and engineering, says the creation of the V-10 wasn’t a foregone conclusion. “The development of the V-10 started three years ago, and we spent the first 12 months thinking about what we wanted to accomplish before deciding how to get there.”
Using computer simulation software, Mercury engineers started with performance goals that included optimal torque curves. They tried countless virtual props and gear ratios before settling on displacement, then the number of cylinders. “We looked at several different configurations,” Reid says, “and we even considered a supercharged V-8 package before deciding on a [naturally] aspirated 5.7-liter, V-10 solution.”
Reid says the design process started with what consumers and boatbuilders wanted and needed. While the 600-hp Verado V-12 outboard was designed as a no-compromise engine for premium boats, some of its features, such as the independently articulating lower unit and two-speed transmission, didn’t create enough bang for the buck on the V-10. “We wanted to create maximum value that’s appropriate not just for multiengine offshore boats, but also for single-engine platforms like pontoons and bay boats,” he says.
Different Iterations, Greater Flexibility
The final configuration of the V-10 has more in common with the V-8 than the V-12, but making it involved more than just adding a couple of cylinders. “Aside from the same pistons and connecting rods,” Reid says, “a lot of the other parts are different.”
Because the V-10 will appear on larger offshore boats, it has a 35-inch lower-unit iteration in addition to the 30-, 25- and 20-inch versions available on the V-8 platform. “It also had to be stronger to withstand the forces generated by high-speed offshore boats,” Reid says.
But despite the two extra cylinders, reinforced parts, Mercury’s Advanced MidSection, and a larger lower unit that generates more lift, the V-10 weighs just 695 pounds, which is only 95 pounds more than the V-8. A new Revolution X prop with diameters up to 18 inches was developed to fit the larger lower unit bullet. The V-10 shares the same 150-amp alternator as the V-12, and there’s an option allowing the V-10 to be switched to either 12 or 48 volts to be compatible with traditional electrical systems or new ones like Fathom e-Power that eliminate the need for a generator.
The electric steering option is designed to provide excellent feedback to the driver, and the effort needed to turn the wheel can be adjusted to owner preference. This design reduces power consumption by 50 percent, according to Mercury, and cleans up the installation by eliminating hydraulic hoses. And like the V-8 platform, the V-10 can be mounted on 26-inch centers, which should make repowering less complicated.
Performance Numbers
While the V-10 Verado may be Mercury’s quietest engine ever, listening to a quad-engine start-up sequence from behind is guaranteed to be a showstopper that begins with an explosive growl. It quickly settles into near silence when the listener moves to the cockpit.
Like the V-12, the V-10 has no water streaming or telltale splashing the water’s surface, an omission that knocks down the sound level. I measured a V-10 400 from just a couple of feet away at idle, and it registered 57 decibels. With the engine off, the ambient sound of the lake was 52 decibels. Mercury claims this engine is 45 percent quieter at cruise than a competititve outboard.
I tested the V-10 on a variety of boats, but the one that best showed off its acceleration prowess was the Avalon 25 Catalina pontoon with twin 400 Verados. Acceleration was linear and strong; the extra displacement seems to have replaced the supercharger without detriment and should improve overall longevity. Time to plane was 2 seconds, and the engine ripped to 26.1 knots in just 4.1 seconds. Top speed was a hat-extracting 61.4 knots.
Curious about the performance of the 350-hp version, which is identical to the 400 except for engine mapping within the engine control unit, I checked out a Scout 365 LXF rigged with twins. We had about 1,200 pounds of human cargo on board but still got on plane in 3.1 seconds, to 26.1 knots in 7 seconds, and to a top speed of 57.5 knots. At 4,500 rpm, we saw 40 knots with a fuel burn of 43.8 gallons per hour. Even better, the engine runs at full power on 87 octane gas.
Pricing for the 350-hp V-10 is approximately $37,000, while the 400-hp V-10 is estimated to be around $41,600. The models give Mercury Marine a line of new platforms to power most boats larger than 20 feet and sets Mercury up for expansion well into the future.
This article was originally published in the January 2023 issue.
