I'd say these short distances are not good for a new engine, as it will not reach operating temperature, as above, new engine = poor consumption initially. Also I'm not sure about restraining a new, cold engine on ECO day in and day out will produce long term benefits for either your pocket or the life of the engine ! Modern engines need to be 'used' during the running-in period as well. A good investment for the longevity of the engine and your pocket is to drive it to the manufacturer's guidance, as well as a bit of occasional hard driving up and down the rev band (not to red line), will do it no harm. Most engines these days come ready to be driven progressively, with little bit of mechanical sympathy of course. Enjoy.
Mike