ANGEL OIL

Angel Oil summary:

In a future where cyborgs are more common than fully flesh and blood humans, a girl goes out to seek oil when her family's ration gets cut off. She needs to get it quickly so her grandmother's heart doesn't burn out, but no one has ever gone up above to the ration center and returned alive... (Note - the first four chapters were published in the four 2007 editions of Quarterly S, the fifth chapter was published in Shoujo Sekai in 2010.)