Hypertech 42006 Max Energy Power Programmer for Crown Victoria/Grand Marquis/Town Car 4.6L 2005-2009 Power tuning for regular, premium and E-85/Flex fuel vehicles Adjustable top speed limiter and engine rev limiter (not available on all vehicles) Speedometer/odometer recalibration for non-stock tires and rear end gears (not available on all vehicles) Automatic transmission shift point and shift firmness adjustments (most applications)