Car hire as an accident replacement

Hello, after I see how intensely here some pure people deal with the whole thing, it would be nice if someone could help me further. I get a rental car due to an accident from the opposing insurance and had never had one before. As a budget they set me 50 euros per day. I would hand the car in on Fridays and pick up Mondays. Because of my still young 21 years only Sixt is in question. The current car is quite well motorized with 160 hp, even the equipment can be seen. I could rent both in Ludwigshafen, as well as in Mannheim, the selection of available vehicles seems quite large. Actually I wanted to rent the class “LSMR” (60 euros per day), but this is often discouraged from doing so, why is that? What could you recommend to me? I like to drive quickly and comfortably, would the class “LDAR” be an alternative? Diesel would be better if e But if the big motorizations are mostly only available as gasoline, I would take one of them. So, what can you recommend and suggest to me there =) I will probably drive 700 km over the three days, as there is a lot to be done.