The number four. It’s the quantity between three and five, the sum of two plus two, and a myriad of other mathematical combinations and functions. And did you also know there is only one animal on Earth that has four knees?

Four is also the number of new four-stroke engines in Mercury Marine’s Verado Series. The 200-, 225-, 250-, and 275-hp powerhouses are the culmination of a five-year, $100-million program which will, according to Mercury Marine, “produce the most sophisticated marine propulsion system in history.”

When the mission to develop these engines began, it was given the code name Project X by its planners and engineers who wanted to offer a line of high-horsepower, four-stroke outboards with excellent acceleration, speed, and durability that would set a new standard in the industry. But they wanted something more, which is why Verados also have an integrated steering and control system.

To deal with performance, all Verados are supercharged using a system developed with IHI Turbo America. By forcing more air into the combustion chambers, it enables the engines to develop big-displacement horsepower out of a smaller-displacement block. For example, a 250-hp outboard would normally use a 3.0-liter block; the Verado’s displaces just 2.6 liters. All four engines are also straight sixes with 24 valves; direct-acting double overhead cams; computer-controlled, sequential multiport electronic fuel injection; and 1.85:1 gear ratios.

For sound attenuation, Verados have an idle-exhaust relief and low-pass acoustic system, as well as a high-performance acoustic foam liner in the top of each engine’s distinctive cowling. Couple that with a highly tuned intake resonator, and the result, says Mercury, is a super-quiet engine. It claims the system reduces intake noise by 14 dBA from midrange to WOT. Furthermore a closed-cell acoustic foam liner inside the “chaps” absorbs high-frequency sound from both the engine and drive train. Finally, Mercury’s Advanced Midsection mounting system cradles the engine at its center of gravity to reduce vibration transmitted to the boat.

With such a complex engine, quality control is crucial. That’s why as each Verado part comes off the assembly line, it is subjected to constant measurement and testing. To ensure optimum quality, the blocks, cylinder heads, and crankcases are cast by Mercury in its own foundry in Fond du Lac, Wisconsin.

Besides using the latest mechanical engineering, the Verado is also intelligent. Mercury’s SmartCraft digital engine-management system monitors all vital systems and delivers that data right to the operator at the helm. Thanks to SmartCraft, each engine employs Mercury’s Digital Throttle and Shift (DTS) system, first introduced with the OptiMax engines in 2002, which eliminates control cables. A programmable two-speed trim and tilt is also standard, as is electro-hydraulic power steering courtesy of a small hydraulic cylinder and pump mounted inside the vessel.

In the highly competitive four-stroke market, Mercury is betting its Verado line will not only run with the established outboards, but outrun them by taking technology to the next level. As soon as the first Verados come off the assembly line and are mounted on transoms, PMY will test them and report back the findings.

And by the way, the only animal on Earth with four knees is the elephant.

Mercury Marine Phone: (920) 929-5000. www.mercurymarine.com.