Captain Michael Howorth looks at the development of marine diesel outboards, their benefits and how they are competing with the traditional gasoline outboards
Ironically it is just as the car industry prepares to do a complete u-turn and declare diesel, once thought of as being a cleaner alternative, the bad guy that diesel is now beginning to become more fully embraced in the outboard engine world.
The question is; will diesel catch on and displace the gas guzzler or will it too be given the kiss of death by the tree hugging environmentalists? Diesel engines are said to be ‘lean-burn’, meaning they use less fuel and more air to get the same performance as a petrol engine does. According to the statistics, diesel engines offer between 30 and 35 per cent greater fuel economy than comparable gasoline engines. So, while diesel fuel contains slightly more carbon than petrol, overall CO₂ emissions of a diesel engine tend to be lower. The higher energy density also means that burning a litre of diesel emits more greenhouse gases than burning a litre of gasoline, about 15 percent more, to be specific.
One notable company Cox are pushing the boundaries of marine diesel engines with its sights firmly set on commercial and military markets, but they understand that the marine leisure business is also lucrative. The company means business and has built its team with ex-Formula One engineers and management.
The irony of this whole diesel versus gasoline saga is that, rather like the very first motor car, the first ever outboard motor was in fact powered by electricity. Designed by Gustave Trouvé, it weighed just 5 kilograms and was patented in May 1880. In the future will the all electric outboard engine kill them both off?