Final answer:
Fuel efficiency comparison between an airplane that gets 90 mpg per passenger and cars requires considering the fuel efficiency (mpg) of vehicles. Hybrid and electric vehicles may reach or surpass this level, but they are not common.
Step-by-step explanation:
The fuel efficiency of an automobile and how it compares to an airplane is a matter that can be calculated by considering the miles per gallon (mpg) metric. Assuming an airplane gets 90 mpg per passenger, one would have to compare this with the fuel efficiency achievable by cars. Finding cars that offer comparable or better fuel efficiency per person can prove to be a challenge, as not many vehicles achieve this high level of efficiency. However, with the advent of hybrid and electric vehicles, some models have begun to approach or exceed this benchmark. Since this performance figure is an average estimate, individual driving habits and the actual number of passengers can significantly affect a car's practical fuel efficiency.