Related Clues:

• Prefix with "logical" or "system"
• Green mode for some cars
• Prefix with friendly or car
• Prefix with 51-Down
• Friendly prefix
• Italian scholar Umberto
• Good for the planet, for short
• __-conscious: green-minded
• "Friendly" lead-in
• Car mode that dampens acceleration
• Prefix for "logical" or "tourism"