Interfaces with static fields in java for sharing 'constants'

I do not pretend the right to be right, but lets see this small example:

public interface CarConstants { static final String ENGINE = "mechanical"; static final String WHEEL = "round"; // ... } public interface ToyotaCar extends CarConstants //, ICar, ... { void produce();
} public interface FordCar extends CarConstants //, ICar, ... { void produce();
} // and this is implementation #1
public class CamryCar implements ToyotaCar { public void produce() { System.out.println("the engine is " + ENGINE ); System.out.println("the wheel is " + WHEEL); }
} // and this is implementation #2
public class MustangCar implements FordCar { public void produce() { System.out.println("the engine is " + ENGINE ); System.out.println("the wheel is " + WHEEL); }
}

ToyotaCar doesnt know anything about FordCar, and FordCar doesnt know about ToyotaCar. principle CarConstants should be changed, but...

Constants should not be changed, because the wheel is round and egine is mechanical, but... In the future Toyota's research engineers invented electronic engine and flat wheels! Lets see our new interface

public interface InnovativeCarConstants { static final String ENGINE = "electronic"; static final String WHEEL = "flat"; // ...
}

and now we can change our abstraction:

public interface ToyotaCar extends CarConstants

to

public interface ToyotaCar extends InnovativeCarConstants 

And now if we ever need to change the core value if the ENGINE or WHEEL we can change the ToyotaCar Interface on abstraction level, dont touching implementations

Its NOT SAFE, I know, but I still want to know that do you think about this