Here is the response I got from Granatelli:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">This replacement unit features 47% more airflow capacity than the stock sensor and state-of-the-art hybrid electronics. The advanced, active-electronic module packaged within the sensor provides improved control of injector timing, contributing to a performance gain of 10-15 horsepower at the rear wheels. This unit installs in minutes, and is legal in all 50 states. The sensor is housed in a rugged, high-impact, injection-molded body to reduce heat soak, which can alter sensor performance.
Installation does not affect mileage or drivability under normal conditions. </div></BLOCKQUOTE>