There has been clamoring for decades vehicle manufacturers to improve fuel mileage. Granted there are hybrid and electric vehicles with improved fuel mileage, but they are either very expensive and/or impractical.
The solution is to cease powering all vehicles with gasoline engines. Instead, install diesel engines in all vehicles. In 1984, technology had developed such that Volkswagen was able to manufacture a Volkswagen Rabbit that got 50 miles per gallon (highway). The vehicle used a diesel engine to achieve this mileage.
Today, diesels run much quieter and cleaner. Currently, it is not uncommon for many vehicles with diesel engines to achieve 40 to 45 miles per gallon.
The change would help the following: improve everyone's budget; severely decrease the chances of a vehicle catching on fire during a crash; lessen our dependency on foreign oil.