@SuperDicq @thatbrickster @kerosene Even the emissions are nothing compared to all the people driving to see the race.

There are tradeoffs - you can go for higher fuel efficiency, but worse noxious emissions (slightly lean), or less noxious emissions but more fuel burn (slightly rich), but I'm not aware of any car where it's easy to adjust the engine configuration to improve the emissions.

It seems the most energy efficient way to extract energy from liquid fuel is a fuel cell, but that's expensive.