The new standards are part of a broad push to get more Americans into electric vehicles, and reduce the environmental cost of driving.
The new standards are part of a broad push to get more Americans into electric vehicles, and reduce the environmental cost of driving.
Nothing for the first five years then all of it on the sixth?
When a new car model with a new engine comes out, is it all at once? Why don’t they put out the new engine in bits and pieces? Not how it works.
There’s plenty you can change to improve fuel economy without replacing the entire engine design.
Fuel maps (potentially at the expense of power)
Transmission shift maps (at the expense of acceleration)
Lighter materials elsewhere in the car (this one actually is better for performance too!)
Better stock tires
Final drive ratio (again, sacrificing acceleration) or gearing in the transmission if necessary.
Compromises will be have to be made for sure, but they can be spaced out so all the legwork doesn’t have to be done at once.
Of course I didn’t even mention hybridization because that’s not a minor change, but some manufacturers might still opt for it and you could keep the same engine technically.
Those are such small things. Not even sure you can do some because of the way mileage is calculated - pretty sure part of it is “accelerate from this speed to this speed in this time, so many times”.
Ah fair, some might have more effect in real life than tests.
Still, timing and fuel infection changes alone can change fuel economy by a lot without necessitating a new block or head design.