Lives up to the Sales Hype! Gas and Diesel both!
Programmed my 2003 Lincoln Navigator 5.4 liter engine after upgrading to a standard K&N filter (replaced the stock filter only), mileage went up 1.8 mpg after programming. Then used the Cortex Super on my 2008 Ford F250 Super Duty 6.4 liter diesel (you are allowed 2 vehicles for programming). Mileage went up over 2 mpg on the diesel. Unit was easy to update, easy to use. Pricey but worth it, will pay for itself in less than a year, especially with diesel at $4 plus per gallon.