Had a 1990-something Olds 98 that got amazing MPG. We were really doing well by that era with decent sized cars that got great mileage.
But then cheap gas persisted - the politicians could not see to raise the taxes to raise the price to keep usage (and imports) low - then the SUV craze kicked in, the China and India economies went wild - then oil went to $150 a barrel - it all collapsed - and it's now starting all over again...