Mercury Verado 300 HP Captain's Report

Mission

The mission of the Verado 300-hp engine is to be a robust 4-stroke engine offering strong low end torque, superior acceleration with reliability, low noise, smooth shifting and superior anti-corrosion protection needed in an offshore saltwater environment.

Distinguishing Features

The new 5.44-inch gear case has been designed with strengthened internal components, built specifically for saltwater offshore boats over 23-feet in length and over 5000 lbs. In these applications the new gear case can handle being run more aggressively, with the periodic ventilation that comes in rough sea conditions.

Supercharged and Intercooled. The Mercury Verado is the only standard production, large volume supercharged outboard engine made. Because it is supercharged this 6-cylinder engine can produce as much horsepower as other outboards with greater displacement. Since the supercharger compresses air at relatively low rpms it can provide superior acceleration from a standing stop.

In conjunction with the supercharger, there is also an intercooler, which reduces the temperature of the compressed air prior to entering the combustion chamber. This combination of compression and cooling puts much more oxygen in the cylinder for more powerful combustion.

In addition there is an Electronic Boost Pressure Control which helps to regulate the pressure regardless of temperature, pressure and altitude delivering consistent performance with very little horsepower loss over a naturally aspirated design.

As with any offshore engine, there are also several sacrificial anodes positioned on the engine. The last area is the supercharger, which has been equipped with ceramic coated rotors and a marine grade anodized aluminum housing.

This engine is offered with a Exclusive 3-year Limited Corrosion Warranty, in addition to the standard 3-year overall warranty. Both are Factory-backed by Mercury.

The pressure charged block technology uses a "long bolt" engine design that keeps the powerhead in a state of constant tension. This not only provides excellent durability, it offers a valve train that requires no adjustments thanks to the computer generated shim selection manufacturing methods.

SmartCraft Management system Mercury’s SmartCraft instrumentation provides vital engine information such as the Engine Guardian to the operator. When a problem is detected an either a Visual or Audible alert is sent to the instrument panel and engine power is automatically reduced, advising of a concern and provide a get-home capability.

Performance Numbers

We have tested the Mercury Verado 300-hp engine several times in a single, twin and triple configurations, in differing types of boats -- a single engine in a Boston Whaler 230 Vantage; twin engines in a Boston Whaler 320 Outrage offshore center console, and a triple engine set-up in a Boston Whaler 370. The results were--

WOT Speeds--

Single 300. The 230 Vantage weighed in at 4,820 lbs. (2,186.3 kgs.) and with a single 300 we recorded a top speed of 43.1 mph at 5950 rpm with a 14-1/4 x 18 x 4 ss Revolution prop. She burned 29.8 gph at WOT.

Twin 300s. The 320 Outrage weighed 9,310 lbs. (422.9 kgs.) for the test and reached a top speed of 51.5 mph at 6300 rpm with 14-5/8 x 17 x 4 Revolution ss props. This boat burned 59.0 gph at WOT.

Triple 300s. The 370 Outrage weighed 16,690 lbs. (7,586.3 kgs.) for the test and reached a top speed of 50.7 at 6400 rpms. Prop geometry was not available at the test site. Fuel burn was 87.0 gph.

Test of Boston Whaler 230 Vantage with a Single Mercury 300-hp Verado

Test Results for a Boston Whaler 320 Outrage Powered by Twin Mercury 300-hp Verados

Test of a Boston Whaler 370 Outrage powered by Triple Mercury 300-hp Verados

Best Cruise Speeds

Single 300. On the 230 Vantage, best cruise was at 4000 rpm pushing us along at 26.6 mph while burning 10.2 gph for a range of 260 statute miles.

Twin 300s.Best cruise for the 320 Outrage was recorded at 4000 rpm at a speed of 26.7 mph where the combined fuel burn for both engines was 20.4 gph providing a range of 353 statute miles if calculated with a 10% reserve.

Triple 300s. Best cruise for the 370 Outrage was recorded at 4500 rpm at a speed of 33.1 mph where the combined fuel burn was 34.9 gph providing a range of 384 statute miles with a 10% fuel reserve.

Sound Levels

BoatTEST.com takes all sound readings at the helm and several variables play a factor. Boats create different wind and water noises at the same speeds and the decibel meter is not able to distinguish engine noise from wind and water sounds. Also, the harmonics of boats are all different, even among the same model to some degree. In other words the same engine placed on two different boats will likely have two different sound readings at any given speed or rpm.

With that as a caveat, our sound tests of the three boats powered by Verado 300 HP engines fall within OSHA industrial guidelines. At idle, our readings for both single and twin Mercury 300s were in the low to mid 60s dbA, which is remarkably quiet. We captured what appears to be an anomalous reading at idle for the triple installation which dropped to 69 for 1000 rpm which was consistent with the other two tests.

Incidentally, two engines are not twice as noisy as one, nor are three engines triple the noise level of one.

Working on Noise. Mercury has engineered this engine to reduce sound and vibration. One example of this effort is the exhaust relief system which is designed to reduce sound at idle.

Another item is the Verado multi-chambered intake sound attenuator, where the air entering the engine is ducted through specially-shaped and sized chambers to reduce overall noise. The company has also applied acoustic foam lining along the upper cowling and lower cowl to absorb high frequency noise from the engine and drive shaft.

Warranty

The 300-hp Verado carries a standard 3-year limited warranty, which is non-declining. Certain boat brands (and we assume all Brunswick-owned companies) which "have met the requirements for the Mercury Installation Quality Certification Program carry an additional year of warranty on the engine," according to the company. That means a 4-year top-to-bottom warranty. This warranty also extends to the controls and rigging when installed by a factory-authorized builder. In addition, there is a total of 6 years of anti-corrosion warranty as mentioned above.