Too high fuel consumption at CDI Smart

Hello we bought us at the beginning of the year n new CDI for2 Smart Passion Bj2006. Now this has a considerably increased sprite consumption than our old CDI Smart. ok that had the smaller tires this does not make out 1.5l. In purely computer terms we come with a tank filling 300 km far which are then always about 18l diesel. These are then about 6 l to 100 km. That is a bit much for the CDI Smart… We were now already with a consumption measurement in the smart center according to PC li If the flow rate at 4.7 l is still heavy but better than 6 l. The smart dealer can’t deal with our actual consumption of 6 l Smart prescribes the test with the read out via the PC. So the problem with the high consumption –> purely mathematically from petrol station to petrol station with 6 l still exists! Can one of you please help me here… with our old Smart we are with a tank filling and the same distance at approx. 450 km i Comen mmer Since you could already think about buying a polo or something so the smart is a pretty swallowing woodpecker!