Gasso's name and logo are both plays of Esso. Like Tosser and Going it maintains a much smaller presence in the state and is likely outcompleted by the dominant Xoomer petroleum company. Its company motto is "We Have Gas!".
The existence of Tosser fuel pumps attached to The Welcome Pump Bar in the town suggest that it may be competing directly with Tosser or that there is some level of business cooperation between the two companies.
It has an interior that isn't accessible without cheats. With cheats the player would have to spawn a jetpack and enter the Blue Hell through a weak spot in the game (the Mulholland Safehouse would be the closest with a wall close to the around the back) and fly to the underside of the shop. The room in the back is the only entrance in because it is not solid, but the front room is. Also, falling through the back room without a jetpack would cause the player to keep falling without end.
The filling station itself is the setting for the mission Tanker Commander when the player aids Catalina in stealing a tanker trailer containing fuel. The glass appears to have several bullet holes in it, showing that it has foiled previous robberies. This explains the owner's confidence when Catalina approaches him at gunpoint.