Don't make major changes (chips or similar) until off warranty. You can use air filters and exhaust cat-back systems without affecting warranty.
Banks system is probably the best method. You can also get auto transmission kits to improve the shifting quality.
Look for reviews of Banks or other upgrade systems on Ford V10 (engine used on many lines of Ford trucks) to see what really happens before/after. Often the numbers coming from an unbiased test are smaller than the advertised amounts.
Bottom line - no cheap or easy solution to upgrading horsepower, torque or gas mileage. OR my V10 would have it!!
