With virtually the same horsepower, which is the better option for rugged offshore work?
Our two 33-footers were not tested on the same day or in the same location, but comparing their performance numbers is still useful because they are identical hulls—and are very close in horsepower (700 vs. 750 hp).
Different Strokes for Offshore Folks
At the same speed of 36 mph, the two-stroke and four-stroke powered boats get an identical 1.3 miles per gallon. Bottom line: You can get the same fuel economy, according to these two separate tests, with the TWO four-strokes compared to the THREE two-strokes.
The Hydra-Sports 3300 CC with the twin F350s achieved its 36 mph at 4000 rpm, while the two-stroke powered vessel hit that same mark at 3500 rpm.
Here’s why: two-strokes and four-strokes operate on different powerbands. Therefore, when evaluating boats with engines that use different technologies (2- vs. 4-stroke), looking at performance numbers at similar speeds—as opposed to RPM increments—is the most effective way to compare fuel economy.
The F350 and other 300-plus-hp four-strokes allow the boat owner to avoid the extra purchase cost and fuel consumption of that extra engine, whether it’s a second, a third or a fourth. And today, these engines are so reliable that the appeal of that additional engine has lessened. Considering this and the comparable mileage between our two test boats, we’d give the edge to the 3300 with the twin F350s.