I came across this article that said they are often slower, the larger cargo ships at least. https://www.theguardian.com/environment/2010/jul/25/slow-ships-cut

I came across this article that said they are often slower, the larger cargo ships at least. https://www.theguardian.com/environment/2010/jul/25/slow-ships-cut-greenhouse-emissions https://www.theguardian.com/environment/2010/jul/25/slow-shi...