Gasso is a small petroleum company that operates a lone filling station in Dillimore, Red County, San Andreas in Grand Theft Auto: San Andreas. It's company motto is "We Have Gas!" Its name and logo are both plays of Esso. Like Tosser and Going it maintains a much smaller presence in the state and is likely outcompeted by the dominant Xoomer petroleum company.
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.
The filling station itself is the setting for the mission Tanker Commander when the player aids Catalina in stealing a tanker trailer containing fuel. It has an interior that isn't accessible without cheats. With cheats one 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 window of the station has a label that says "Max Pane - Bullet Proof Glass", an obvious reference to the Max Payne series. The glass also appears to have several bullet holes in it, showing that it has foiled previous robberies. This explains the owners confidence when Catalina approaches him at gunpoint.