I have been driving the C1 hdi for 5 months now – now more than 10,000 km – and am totally disappointed by the consumption. In everyday life on short distance the car needs about 4.9 liters, if it gets colder, also already 5.3 liters diesel. A holiday trip to Hossegor/France resulted in a consumption of 4.9 liters at motorway speed (Tacho 130). Once I deliberately drove 200 km slowly. That was on the highway in warm weather and I stayed at Tacho 120 km/h. In Hossegor I once practiced in restraint. So I managed to get on the highway at 30 degrees and strolling around at 90 – 100 km/h 3.95 liters. After the EU consumption values I had promised myself less. Since I keep all known savings tips, I hoped for a consumption of 3.7 liters. Unfortunately I did not even reach this nearly. Who still has experiences? Write! It is striking that my C1 is remarkably inelastic. In the 4th gear you should be able to reach 4.5 liters of diesel per 100 km. do not drive under 60, in 5th gear not under approx. 90 km/h, otherwise it feels extremely undertouring and runs quite unevenly.