It is thus ironic that while the battle at Alam-Halfa was fought in good part for possession of the Middle East oilfields, its outcome was determined by the amount of fuel available to the Deutches Afrika Korps. There was perhaps enough for one last attack, although much depended on the quality of the sand on Rommel’s route of advance. This required the panzers to move thirty miles by night over minefields and “unknown ground.” The latter might prove more of a problem than the former: tanks moving over “soft” sand used up three times as much fuel as on “firm” (stony) sand and the difference could prove crucial.
– Terry Brighton, Patton, Montgomery, Rommel – Masters of War, pg. 126