According to CNNMoney.com, when Ford's new flagship Lincoln sedan, the MKS, goes on sale later this year it will be available with all but one of the main features usually found on full-size luxury cars: the V8 engine.  

But V8 engines aren't needed in many of the big luxury cars anymore, according to Ford and General Motors. New, more sophisticated V6s offer nearly the same performance with better fuel economy. The top-end engine in the new MKS sedan, to be offered within a year of the car's launch, will be a twin-turbocharged V6 with direct gasoline injection.

Other car brands have seen similar shifts, according to Power Information Networks data. Buyers of the Chrysler 300, Mercedes-Benz E-class and the Cadillac SRX crossover SUV, which all offer V6 and V8 versions, are shifting away from V8s toward V6s. Industry experts attribute the shift to more consumer interest in both technology and fuel economy.

CNNMoney.com reports V8 engines won’t go away altogether, industry sources say. There will still be certain vehicle types in which V8s will be a must-have, such as big pickups and SUVs that need them for low-speed towing and hauling power.