questions to legacy 2.0 R lpg/ purchasing decision support

Hi people, I have a specific offer for a 165 ps legacy with liquid gas system including guarantee. so make me think if this is really more economical than my current diesel. so it would be gratifying if drivers of such lpg models could share their experiences. 1. is the gas system maintenance-free or do additional costs come in addition to the inspection? 2. how much gas do you refuel real if the gross volume according to dealer is 52 liters? 3. how far do you get with an inspection? filling/consumption? at the end of the week I regularly drive almost 600km a distance and do not want to have to refuel 3 times, especially since I already looked at the stations directly at the autobahnen it looks quite bad there, if the also at night should have open. (I mean no backyard refueling points of car dealers, which close 17 clock, but correct autobahn refueling points) 4. how much does the weight of the gas system, which one carries for a car life additionally? 5. there was a m start problems with the gas system, so you had to adjust several times to the dealer? 6. is the motor enough for 165 ps and what do you say about the sound? thanks for answering the questions! 😉 mfg