domestic consumption z28

Greetings like in the other post already written consumes my 96 he geiger camaro z28 up to 30 l super plus. (is an automatic) given a consumption of 12 – 18 l that you can hardly drive the car with 12 l is clear to me, but I can hardly move the car under 20 l. (Oh yes, and I can also drive *grins*) that the consumption is slightly higher because the car sharp camshafts, cylinder head processing, chip, fan manifolds, runnau spuff system and wider mature has is normal, but that this consumption comes on unlogical 30 l with sporty driving is already the hammer. drive the car for 2 years, was always like that. also the previous owner has criticized this spritfresserei. I never thought much about it, is not an everyday car and the fun it is always worth to blow away 30 l, but maybe there is something wrong with it? am not now the screwdriver or motor expert who has the full insight…maybe if one of you is advised? the car is cared for by geiger münchen, most would have to be a concept, they have never noticed anything in the direction.