Why haven't there been any diesel-electric hybrids yet? It seems like the perfect application for a small, 2-4 cylinder efficient diesel driving a light and com

Why haven't there been any diesel-electric hybrids yet? It seems like the perfect application for a small, 2-4 cylinder efficient diesel driving a light and compact neodymium generator. Trains and ships and submarines have been using diesel-electric hybrid power for over 100 years now [1] , so it blows my mind that this technology is still considered novel / new / and isn't totally refined yet. 1. http://en.m.wikipedia.org/wiki/Diesel_locomotive#First_functional_diesel_vehicles http://en.m.wikipedia.org/wiki/Diesel_locomotive#First_funct...