I own an 05300 with the 3.5 V6. The 4speed automatic in my car shifts by itself at around 6300 RPM. I would like to know just how fast the car can go. The problem is in fourth gear the car stops accelerating at 185kmh and the tach is only showing 3900 RPM. I don't drive like a lunatic all the time but am curious as to how fast the car can go. I was told that a Jet chip would defeat the speed limiter but it did not. Money wasted. Does anyone know how I might defeat the speed limiter just to see.