Abstract: The present invention relates to a device for feeding liquid fuel to a diesel-type I.C. engine, said device comprising a pipe feeding fuel to the injection pumps of said engine, said feed pipe forming a feed loop and comprising a pipe for admission of said fuel, means for treating and circulating said fuel and a pipe for introducing additional liquid into said fuel, characterized in that the point of connection of said pipe for introducing additional liquid to said fuel feed pipe is located immediately upstream of that part of said feed pipe which supplies said injection pumps of said engine, and in that a closure valve, capable of closing said feed pipe, is located immediately downstream of said part of the feed pipe which supplies said injection pumps of said engine.