No simple decision 😉

Hi guys, I’m very confused and don’t know any more. To my location: I drive 120km daily back and forth to work (60km easy) that makes about 30Tkm a year. Currently I drive an Opel Astra Z20LER with LPG conversion. This is supposed to be economical, but with an LPG consumption of about 11-12L/100km the Srit costs are even more expensive than with a diesel that consumes about 6L. In addition, a D should last longer. On the Astra I have 160Tkm down and so slowly My problem: 1. I could buy for about 18-20TEUR e.g. a 320d which has quite good consumption values and a quite stable engine. But at 30Tkm a year I lose just too much value ;( 2. That a 320d with all the technical fuel saving sounds consumes hardly less than e.g. an Audi 80 TDI (20J old!!!)(Laut Spritmonitor.de) has already surprised me very much. Since the A80 is also an ar I have also thought of this vehicle… But… unfortunately no green badge ;( 3. Alternative would be a small car like Corsa 1.3 CDTI. Cost-effective, little taxes etc.. But does it hold me really long? A 320d or similar would I place my wife as a second car and really only need a car for the way to work. He should be economical, keep long and I should be able to carry out small repairs myself (accessibility). Since I have never before been able to carry out small repairs. (and don’t know any) because of a plaque, I would even accept a possible penalty. What would you do and for what reason?