I played MP 2 times. In the first session I was able to refil one of my mates for about 200L then in the second session on other map I had a chance to refuel my teammate for about 350L and then I got achievement Fuel Tanker. I was surprised because I knew that it required 1000L and I was sure that I was not able to refuel for that many liters. I checked achievements and I saw that!>>>
LOL! WTF! xD I think that even in all sessions of single player I was not even half to that number and I played only on Hardcore 