I’ve a 2019 Tiguan 2.o TDI 2wd R-Line Tech – on a run (140 miles) I get about 47 mpg. Around town I’m getting 26/27 mpg. I run it purely on BP fuel (and ultimate on the odd occasion to protect that DPF). I let the car warn me when its low (50 mile range) and then I tank it – costs me around £70 to fill. This usually lasts me about 3 weeks.