Related Clues:

• Helium, eg
• Spirit of US motorists so genial, it turns out
• THIRD PART OF 23
• Hydrogen, eg
• Fuel for American state senate leader
• eg CO2
• eg Oxygen
• Petrol (USA)
• Fuel is needed to reverse slump
• Fuel; idle talk
• Oxygen is one
• e.g. Oxygen
• Hydrogen possibly
• Flop back to talk to
• Petrol can be an anaesthetic