Aircooled VW South Africa

Hi guyz im Lorey im hoping u guyz can help me somehow. I've got a microbus 2.1i the model is 1990. I dont know how the petrol consumption should b on these vans but this van is killing me wth petrol. Wen i had just bought the van it was worst, but then had it tuned so that its a bit lean, but im stil not satisfied. I get like 400km from a full tank(85L) What can i do to get the feul consumption much beta with the existing engin?

you can start by tuning it properly instead of tuning it lean.
Even by going lean, you get to a point where it starts using more fuel to make the same power.
Try driving slower - maybe 90km/h. Remember, you are driving a un-aerodynamic brick - the faster you go, the more fuel you use.