Demonoil

Demonoil is an engine lubricant brand. It first appears in Grand Theft Auto Online through Arena War, where its advertising runs on animated screens at Maze Bank Arena. The company also sponsors several Arena War vehicle liveries, placing its name among the event's commercial signage.

The brand appears elsewhere in Grand Theft Auto Online. Demonoil advertising sometimes plays on the television beside the Career Wall in the Arena Workshop. Its name is also displayed in Auto Shops, including a banner, a worn oval logo on the Rancho exterior and a vintage sign showing an older motor oil can.

In Grand Theft Auto: Vice City - The Definitive Edition, Demonoil branding appears on a calendar model in the Print Works, replacing the Pervelli Calendar from the original release. This Definitive Edition appearance is non-canon. In Grand Theft Auto VI's second trailer, a Demonoil sticker is visible on a tool cabinet inside Brian's Boat Works & Marina.