does ram air affect economy?

I drive a 03 dakota year round with the shaker hood. Its a 4.7l ... i do notice a slight difference in mpg in the winter. I usually run around the 17-18 mpg in the summer avg 20 degree Celsius.

When the thermometer dips down below 0 degrees Celsius I notice the mpg runs in the 13-16 mpg range.

I will always be convinced no matter what someone says. More air equals more fuel. Colder air also takes more fuel.

From what i read in most places the dakotas with a 4.7 usually run in the 20 mpg range.

As for vacumn i have no idea.