Tzar , tell him to pump petrol and show u receipt as well .
Then at night pump back full tank show him the receipt .
Well Tzar , this is a common practise , pump full tank for both cng and petrol , but ....
always a but .... vehicle became heavier , thus consumed higher in both petrol and CNG .
U have got any idea how heavy is full tank of petrol ?
Alone CNG is 21.90 kg excluding the tank .
Including CNG + Tank + Full tank Petrol = Very heavy to the already heavy Toyota Wish .