Last diesel car i had was back in 2017, The E250 is now only driven by my dad but i still service it. I recently bought another gas W124 but it's a 4 cylinder gas guzzler and it gets old quickly when you have to drive 500 km each week. A diesel would make sense and for the first time i would be ok with buying something else than an old Mercedes, Probably and Audi A4 B6 or Passat B5. I would like to be able to run WVO too, in a 50/50 mix. What are the most reliable diesel engines that can take WVO for many many miles? The reason i'm thinking about an Audi A4 is because i test drove one and was impressed by the torque and the fuel economy. 45+ MPG is doable. The interior was very nice too with woods and leather. What is your experience with specifically these diesel cars? What else would you recommend?