The general improvement for 2012 cars is better gas mileage. All 2012 cars seem to have that feature.
They don't. Diesels get better mileage and last longer.
There were many different types of cars made in 2012. Mileage varies between them, as well.
A long list of GM cars mostly Buicks
sometimes
Buicks or old Grand Marquis.
101 Cars You Must Drive - 2008 Bond Blowers Buicks Etc- was released on: USA: 28 July 2008
less wind resistance, better fuel mileage
Less weight = better fuel mileage.
Cars don't get better gas or mileage.
The best gas mileage from unleaded gasoline or premium gasoline depends on the car. Old cars get better mileage from unleaded.
Better fuel mileage and cleaner emissions.