Possible Clues:

• Imperial Oil brand
• "Put a tiger in your tank" brand
• Exxon, in Canada
• "Happy Motoring" gas brand, once
• Gas sign north of the border
• Old 'Put a tiger in your tank' brand
• Rival of Sinclair and Sunoco
• Old U.S. gas name
• Petrol station name
• Bygone pump name