Since you are concerned about mileage, a diesel or petrol-hybrid does make sense, and we can see your confusion between the two. Generally speaking, the hybrid would be a safer bet in the long run, given the uncertainty around diesel with the authorities, plus you will also have a quieter powertrain. However, we have yet to drive the hybrid Renault Duster, and this will only arrive in the second half of this year. So, you would have to wait until then.