- March 2004
| ||4.3 MPI/A1
|1 w/ two adult males aboard
5 WOT for Volvo
|2 Optimum cruise-Volvo|
4 WOT for Merc
13 3/4"x23" ss
14 1/4"x23" ss
||Merc Dept. TBM
3003 N. Perkins Rd
Stillwater OK 74075
|Volvo Dept. TBM
1300 Volvo Penta Dr
Chesapeake VA 23320
|1MSRP of Stingray 195LR w/ corresponding sterndrive package
|TOP SPEED (mph)
|Average with one adult male aboard
|Volvo Penta 4.3 GXi/SX
|While MerCruiser and Volvo Penta use the same 4.3L electronic-fuel-injected
engine from General Motors, there are a number of variations in these sterndrive packages.
Aside from different drives, here are some key differences.
||GM MEFI IV
|Digital Gauge Opt.
One of the most plentiful engines ever produced is the General Motors 4.3L V-6. In addition to
finding its way into many GM cars and trucks, this engine has also become a standard powerplant
in many boats.
Fact is, any boatbuilder that makes 17- to 22-foot sterndrive-powered boats is likely to offer
the 4.3L in one form or another as standard or optional power.
Both MerCruiser and Volvo Penta offer versions of the V-6. Each has carbureted and
electronic-fuel-injected (EFI) models in its lineup. While GM delivers the same basic powerplant
to both, MerCruiser and Volvo Penta take slightly different approaches in marinizing the engine
and bringing it to market. The biggest difference in these sterndrive models lies in the outdrive
configurations. Many 4.3L Mercs are fitted with the popular Alpha drive, while the Volvo often
sports the similarly popular SX drive.
With this in mind, we thought it would be interesting to test the two EFI powerplants side
by side to compare performance in terms of acceleration, top speed and fuel economy. To accomplish
this project, we enlisted the aid of South Carolina-based Stingray Powerboats. Company president
and founder Al Fink graciously had each powerplant installed in identical 195LR bowriders. The
195LR is a new model for 2004 and boasts the company's next-generation Z-plane hull design (see
Test Platform sidebar below).
We invited representatives from each engine company to be present during our testing on South
Carolina's Lake Robinson near Stingray's headquarters in Hartsville — this to help ensure
that the engines and drives were operating at peak performance. Assisting us in this regard were
field technicians Don Christman from Mercury Marine and Mark Huddleston from Volvo Penta. To their
credit, both men not only worked hard in their respective areas, but their amiable spirit made our
project all the more pleasant.
To make sure there was no disparity in driving skills and driver weight between the Merc- and
Volvo-powered Stingrays during our acceleration and top speed runs, we used the same test driver
in each boat. That task fell to tireless Mike Weatherford, who has been with Stingray since its
inception and knows how to finesse each of the company's 18 models for optimum performance.
Weatherford was the only occupant in the boat during these runs. The fuel economy numbers,
however, were gathered with two people in each boat. We recorded the data while Christman and
Huddleston drove their respective boats. Hence the top speed is different in the fuel data figures
than it is in the solo-occupant acceleration and speed runs.
To record our performance data, we used a Stalker Acceleration Testing System, which combines
the Stalker ATS Professional Radar Gun with a special Stalker ATS computer software program. The
gun measures the speed of the boat at precise intervals, and then sends that data to the computer
through a cable. The software program assigns time information and then calculates distance and
acceleration rates for each fraction of speed recorded.
Since speed, time, distance, and acceleration are mathematically related, having any two of
these measurements means the other components can be derived with absolute accuracy, and the
software contains the formulas to accomplish this. The software allows you to record a radar gun,
then display the information graphically in any combination of speed, time, distance, and/or
acceleration. It does it all instantly.
Since the entire system is portable we were able to set up a makeshift office right at the
dock on Lake Robinson with a battery pack and two 5-gallon barrels, one serving as a table for
the laptop and another to sit on. Crude, but effective.
Each manufacturers' sterndrive package has certain advantages over the other. MerCruiser's 4.3
MPI with the Alpha drive has a weight advantage, tipping the scale 42 pounds below Volvo Penta's
4.3 GXi with the SX drive. On the other hand, Volvo Penta says the SX's added underwater
gearcase length increases stability, improves handling and positions the propeller farther aft
for a stronger bite, resulting in quicker acceleration.
GM Powertrain indicates that the Vortec 4300 marine engine it supplies is rated at 223 hp,
which is 13 to 23 hp more than the automotive versions. Volvo Penta then calibrates its 4.3 GXi
to be 225 hp at the prop, while MerCruiser rates its 4.3 MPI at only 220 hp at the prop. We did
not check either engine on a dynamometer.
Once of the biggest differences between the two offerings is the choice of electronic control
module (ECM) technology to operate engine functions. Volvo Penta uses GM's MEFI IV, a
fourth-generation ECM that uses hybrid technology to optimize fuel and spark. MerCruiser, on the
other hand, uses the 555 ECM from Motorola, which makes it compatible with Merc's SmartCraft
SmartCraft is a sophisticated technology that can link the boat's power, systems and controls
with a variety of other sensors to provide everything from engine diagnostics and fuel management
to digital throttle and shift control.
Another key difference is that MerCruiser uses a dog clutch in its Alpha gearcase, while Volvo
Penta uses a cone clutch in the SX. The result is the SX drive shifts smoother, and by all counts,
should last longer. The Alpha drive shifts best when it is put in gear quickly; as with an
outboard, don't try nursing it. You'll just grind the gears. It should be noted that MerCruiser
only uses a dog clutch on its Alpha drive; all other Merc outdrives utilize cone clutches.
In our testing, we mated the MerCruiser drive with a Mercury propeller and the Volvo Penta
drive with a Volvo Penta propeller. No propellers from other manufacturers were included in this
test. Both propellers were stainless steel three-blades with 23 inches of pitch.
LET THE GAMES BEGINS
In terms of acceleration from a dead standstill, the Volvo Penta boat reached 20 mph in 4.8
seconds, compared with 5 seconds for MerCruiser—a mere 0.2 second advantage.
The Volvo Penta continued to out-accelerate the MerCruiser by reaching both 30 and 40 mph a
half-second quicker. Interestingly, however, the MerCruiser boat closed the gap past 40 mph,
with both boats reaching 50 mph at the same time: 13.2 seconds. The bottom line is the Volvo
Penta accelerates quicker out of the hole, but the MerCruiser comes on strong in the stretch.
At top end, the Volvo Penta won. We ran each boat in two directions (toward us and away from
us) and averaged the top speed. Volvo Penta posted an average speed of 61.6 mph. MerCruiser, on
the other hand, recorded an average of 60.9 mph.
The final part of our test involved fuel economy. Volvo Penta netted the best miles-per-gallon
usage at slow to medium engine speeds up to 3000 rpm, which corresponds to boat speeds in the 35
to 40 mph range, where the craft will likely be run most of the time. At 2000 rpm, the Volvo
Penta-powered boat was able to plane, whereas the MerCruiser boat was not. Hence, you see a
substantial difference in fuel usage at that point. At 3500 rpm, where both boats ran 42 mph,
MerCruiser took a slight edge in fuel economy. At 4000 rpm, both boats were equal fuel-wise. But
at top end, the MerCruiser recorded slightly better fuel economy.
EFFICIENCY vs. ECONOMY
It should be noted when discussing fuel economy between these two sterndrive packages that Volvo
Penta recommends using fuel with a minimum octane of 89, while MerCruiser recommends 87. The
dollar cost at the pump between 87- and 89-octane fuel should be taken into consideration when
comparing the true economy of one engine over the other. In other words, while Volvo Penta may
use less fuel throughout much of the rpm range, the actual cost may not be that different.
All things considered, the Volvo Penta edged out the MerCruiser in this contest. But the
margin of victory was not overwhelming, so other factors may also influence your buying decision
one way or the other. For example, Merc offers the SmartCraft digital instrumentation upgrade,
while Volvo does not currently have such an upgrade. MerCruiser also has a wider national service
However, if it's bragging rights for fastest boat you desire, Volvo gets the nod.
|TEST PLATFORM - STINGRAY 195LR
When Stingray president Al Fink told us he could get a legitimate 60 mph out of his new
195LR with only a production V-6 for power, he got our attention. Subsequent discussions
led to this project, where we tested the 195LR with, not one, but two V-6's, one from
MerCruiser and another from Volvo Penta. We're happy to report that the 195LR lived up to
everything Fink said it would. Both V-6 sterndrives surpassed 60 mph.
New for 2004, Stingray's 195LR rides on the company's next-generation Z-Plane hull, a
patented design that delivers outstanding performance, as our test results indicate. The
primary difference between the new hull and its predecessor primarily lies in the aft
portion of the running surface. Fink, who is hands-on when it comes to product development,
modified the hull with unique contours to the running surface that now extend beneath both
sides of the integrated swim platform. The intent is to help the boat plane quicker out of
the hole and create three-point contact in the water at faster speeds to provide a
Like previous generation Z-plane hulls, the 195LR has a slight notch in the transom,
which also improves boat performance by permitting the drive to set a little higher out of
the water to reduce drag. In our time behind the wheel, we found the 195LR to maneuver very
well. It has crisp acceleration and turns tightly without any hull-skip or propeller
Compared with other Stingray models in the lineup, the new 195LR has a different seating
configuration, too. A stylish wraparound bench seat accommodates more passengers and is
better suited for socializing. Ahead of the bench are twin bucket seats that swivel and
adjust fore and aft. A large padded sundeck covers the engine and side storage
The bow of the 195LR has also been upgraded with curved lounges in lieu of angular ones.
In addition to making it look more appealing, the new design also allows passengers greater
legroom. Like other models, it has a nonskid step leading to the forepeak for easy boarding.
Beneath the step is an insulated cooler.
Stingray also changed the cockpit by tapering the sidewalls to create more interior room.
Other improvements include a larger swim platform with a recessed (rather than
surface-mounted) three-step retractable ladder, and a lower profile elliptical instrument
panel that gives the helmsman better forward visibility. The passenger's dash has a flat
glovebox with enough room to the side to install personal electronics. In a vertical section
of the dash ahead of the glovebox is the stereo CD system, well protected from the elements
by the windshield. Base engine in this boat is a 135 hp 3.0L sterndrive.
All Stingray boats come with such no-cost extras as custom engine vibration dampers, a
remote oil changing system (with MerCruiser), fuel surge protector, three-year blister
protection as part of the five-year hull warranty and a personal MyStingray.com
website, hosted by Stingray.