Gasoline is sold exclusively by the government in Myanmar. Everybody is allowed three gallons of gas every three days at the government's heavily subsidized price (I don't remember the exact number, but I think it was around $0.18US per gallon). If you need more than three gallons, you have to pay a much higher price more closely resembling market price. The government subsidized this price too after the massive oil price increases we've seen in the last little while, although I think they're trying to phase that out. When they jumped that second price up considerably about a month and a half ago, traffic in Yangon was cut by about 75%, but the government eased up on the price some.
This two-tiered pricing creates a black market opportunity: if you burn less than three gallons in three days, you go to MPPE (the government fuel stations - there aren't many of them, resulting in long lines at peak times), buy your three gallons, then drive to the guy down the street who has a couple gas cans with leaves sticking out of them at the edge of the road. He syphons off your two and a half or three gallons into plastic coke bottles, pays you some money, and then sits there until someone else stops by to buy gas. In Yangon I think there are more of these black market gas stations than proper ones - they're right out in the open, very easy to spot.
To a North American this doesn't sound worth messing with: two or three gallons, and your profit's going to be maybe $0.80 per gallon - but you also have to factor in wear and tear on the vehicle, and the fact that you are actually doing something illegal (I assume it's illegal - perhaps it isn't?). But to someone in Myanmar, that would amount to about 3000 kyat profit for those three gallons, and that's a couple day's wages for most of them.