Hi! Yes we used 4x4 and low gear too lot of time on the BAM road. There is lot of parts with rocks and lot of river crossing. In our case some with approx. 1m deep. We were lucky and dont have lot of mud but usually there is lot of mud on the road. But on the last section we have lot of snow. 40-50cm. So yes 4x4 car is great choice, but not necessary. But you need good ground clerance and snorchel for river crossing.
Hi, is very cheap in thi part of world and no porblem with get gasoline. We usually used GAS (LPG) and the price was funny 0,11 eur cent for one liter (the cheapest one)...