Diminishing marginal returns may have something to do with it. Fuel efficiency for passenger cars has increased by about a third, and larger increases have occurred in vans and small trucks.Relevant graph. But, compared to the maximum efficiency for their types, efficiency is still extremely low. And efficiency for large trucks is essentially unchanged. So I’m not sure we’ve really hit that point that substantially.
Diminishing marginal returns may have something to do with it. Fuel efficiency for passenger cars has increased by about a third, and larger increases have occurred in vans and small trucks.Relevant graph. But, compared to the maximum efficiency for their types, efficiency is still extremely low. And efficiency for large trucks is essentially unchanged. So I’m not sure we’ve really hit that point that substantially.
Yes, fuel efficiency can be increased at the expanse of something else, e.g., cost, safety, etc.