It's not often that consumers choose a V8 engine for its low fuel consumption, but that seems to be exactly what is happening with the Yamaha F350 outboard motor. This sixty-degree engine is a rather high-tech design, featuring 32 valves and double overhead cams to produce some 350 horsepower at the prop shaft. One reason cited for its ability to save fuel is that the engines don't need to work as hard as smaller, high-strung engines.
According to Shane Kearns, who operates a water taxi in Australia, "Over the 35 engine hours clocked so far I have nearly halved my fuel bill with the twin F350 outboards returning a combined 31 liters per hour across a range of harbor conditions and boat loads. I originally thought my fuel gauges were wrong until I started closely monitoring my fuel intake." When first built, his boat featured twin two-stroke engines, which were later replaced with Yamaha four-stroke outboards. His latest F350s not only reduce fuel consumption but also provide additional speed and power, things which don't normally go together.
[Sources: Yamaha and Gizmag]