extravagant vs fuel-saving

extravagant

adj
  • Extreme; wild; excessive; unrestrained. 

  • Exorbitant. 

  • Profuse in expenditure; prodigal; wasteful. 

  • Exceeding the bounds of something; roving; hence, foreign. 

fuel-saving

How often have the words extravagant and fuel-saving occurred in a corpus of books? (source: Google Ngram Viewer )