LPG Consumption Tahoe 5.7

Hi, I would be interested in what your Tahoes converted to LPG consume. My consumption seems to be quite high: I had a Tartarini installed in my 98 Tahoe 5.7 ltr. The fuel consumption is thus 13-14 liters. Gas it needs easily 20 liters; I find the extra consumption quite heavy! Since I had initially noticed on standing vehicle gas odor, I suspected a leak in the system. Was also so and was removed in the workshop. r screw connection was not reasonably sealed. Therefore, I am quite sure that further leaks no longer exist. However, the consumption remained high; a defective thermostat was detected during a further visit to the workshop. Since the LPG control reads and processes values from the thermostat, the cause was assumed here. But the exchange did not work either. Therefore, my question about your consumption values. Remember that it is not a problem with the workshop. Krauter is dealing with JA Automobile in Langenfeld, a major dealer for Suzuki, Dodge, Chrysler, for which LPG conversions are part of the day-to-day business. By the way: I was pleasantly surprised that I received a new tax notice completely uninquired and unexpectedly after the installation and now only half of the car taxes have to be paid (7.36 €/100ccm). So the system pays for itself much faster. I always assumed that the classification of cars with bivalent operation did not exist. t changes and is assumed to be worse each. Greeting wogro