Why did Ford stop making the 7.3 liter power stroke?

I can't comprehend why ford just drop the 7.3 liter and switch to the 6.0 and I heard bad things about the 6.0 and the 6.4 liter. So does anyone know why ford drop the 7.3? I hear the 7.3 are long lasting engines and are bulletproof so if they're such good engines why did they discontinue?

The 7.3 power stroke diesel engine that Ford made was a marvel of engineering. It was strong, ran forever, and… Expensive and not very fuel efficient. To save on costs and to meet demands for more fuel efficient vehicles are the most likely reasons for the switch. Too many fuel economy and warranty issues so Ford redesigned it. Most likely they figured that they could increase reliability and efficiency by making a new engine.

Ford has typically been that way… Always looking to the future. Pretty much all of their engine design in the last 20 years has been geared towards lower displacement, multivalve heads, and large amounts of boost. Unfortunately, this means that the engines have to rev higher and work harder. And in combination with people who don't know how to treat engines, reliability is greatly reduced. People chipping them and pretending their trucks are race cars doesn't help, either. The reason was that the 7.3L wasn't going to be able to pass upcoming (at the time) emissions standards for light duty vehicles. The engine is also marketed as the Navistar T444E and saw use in medium duty trucks and industrial applications.

The choice to discontinue it had nothing to do with fuel economy as the 7.3L had better fuel economy than either it's 6.0L and 6.4L successors. The replacement 6.0 diesel did have a major problem, but only for the first year. To meet the ever tightening regulations on emissions ford and Navistar had to drop the 7.3 PSD in favor of the 6L as the problems with the 6L ended up in court as Navistar ended its relationship after production of the 6.4 ended. Ford then took what they learnt from the three decades of the relationship with Navistar and come out with their own line of power-stroke diesels code named "scorpion".

Too many fuel economy and warranty issues so Ford redesigned it.

Most likely they figured that they could increase reliability and efficiency by making a new engine.

Ford has typically been that way… Always looking to the future. Pretty much all of their engine design in the last 20 years has been geared towards lower displacement, multivalve heads, and large amounts of boost. Unfortunately, this means that the engines have to rev higher and work harder. And in combination with people who don't know how to treat engines, reliability is greatly reduced. People chipping them and pretending their trucks are race cars doesn't help, either.

The reason was that the 7.3L wasn't going to be able to pass upcoming (at the time) emissions standards for light duty vehicles. The engine is also marketed as the Navistar T444E and saw use in medium duty trucks and industrial applications.

The choice to discontinue it had nothing to do with fuel economy as the 7.3L had better fuel economy than either it's 6.0L and 6.4L successors.

The replacement 6.0 diesel did have a major problem, but only for the first year.

To meet the ever tightening regulations on emissions ford and Navistar had to drop the 7.3 PSD in favor of the 6L as the problems with the 6L ended up in court as Navistar ended its relationship after production of the 6.4 ended. Ford then took what they learnt from the three decades of the relationship with Navistar and come out with their own line of power-stroke diesels code named "scorpion".