Ali Mestassi Posted about 2 years ago A conversation with Shell: How can the smarter use of energy and other resources unlock the true potential of cities? I don't know why we should talk about fuel efficiency while "the smartest barrel of oil is the one you don't use". Why don't we make every existing barrel the smartest one? is it impossible? I believe we will have to. We must cope with this addiction of fossil fuels. I always have the peak oil in mind. What are we going to do about that? Until when we will improve the fuel efficiency?