Ok, I've noticed that when I hit 3500 RPMs the engine gets a kick and I accelerate faster. It is similiar to what happens in my dad's Taurus SHO. A second throtle body opens up at 4000 RPM and you can feel it. It was a nice feature as he get 32mpg if he takes it easy but once you get the RPMs up, it takes off. Does anyone know if the same thing is happening in the X's engine? I do not have the service manual and am curious if anyone else has read about it.
Kurt