I installed one of the Tornado fuel savers in my 2003 Chevy full size pickup that has a 4.3 V6. I commute 50-60 miles to work M-F and I thought it would be worth a try. The milage rating for this truck stated by Chevy is 15 - 18 MPG. I do not usually spare the pedal on my commute in, so prior to installing the Tornado fuel saver I was typically getting 15-16 MPG on regular gas. After installation I have been getting 19-20 MPG on regular gas. That is ~ 18% improvement. The improvement you see on your vehicle depends on how good or bad your stock air delivery system is now. The Tornado fuel saver website has data listed for various vehicle and engine types, so that you can see what type of improvement you might expect. I was skeptical myself, but they do offer a money back guaranty, so I gave it try. No regrets here.
