It used to be that equations in the game could only support 4 variables, but with the next update they support six.
They don’t parse brackets yet, but they will work like this:
(you can still use just 3 or 4 variables if you prefer).
The is the new impact of banning low mpg cars.
The equation works out as this:
effect on motorist = 0.05- (((x^2) * 0.14) * (1.0 - ElectricCarTransition)
(basically up to 6 variables are supported, the first one is special case, then the others all get applied in order).
_inv_ElectricCarTransition is a new thing. We now support you adding the text ‘inv’ in front of any variable, and this will then evaluate that as 1.0 - the value of the variable. This makes doing stuff like the above much easier.
So now what this equation does, is it always reduces motorist happiness by 5% plus a further amount equivalent to slight curve based on the strength of the policy (x^2) multiplied by 14%, multiplied by the extent to which people still drive gasoline cars.
Where there are no electric cars and the policy is at max, the effect will be minus 19%. with 100% electric cars, the effect will still be 5% in this case.
There are lots of places modders may find this useful, especially the new inv support, which works anywhere in the equation you could add a named variable.