In most of the US petroleum industry, all the refined products are measured in barrels. It is only pricing that typical goes to the gallon for gasoline.
http://www.eia.gov/dnav/pet/pet_move_wkly_dc_NUS-Z00_mbblpd_w.htm
http://www.eia.gov/dnav/pet/pet_pnp_wprodrb_dcu_nus_w.htm
http://www.eia.gov/dnav/pet/pet_stoc_wstk_dcu_nus_w.htm
Thanks.