Biden is going to bring us back to the horse and buggy!
It will make him feel young again!
I can't find anything about his MPG plans, just that the EPA released a new rule that it cannot control the pollution of any stationary sources other than power plants, so factories and stuff would be unfettered, just like the London Fog intended:
Trump’s EPA launches surprise attack on Biden’s climate rules
The EPA gives rules. The EPA can take rules away.