Reviewed By W S D (PALM HARBOR, FL) Reviewed for a 2001 Ford Expedition —5/20/2014 7:06 AM
Now that I have the Flowmaster Force II installed, I have but a single regret - that I failed to get one years ago. It has a subtle rumble at idle which comes up a bit as you put your foot in, but then stays about the same as revs go up, which frankly amazes me. It never really goes above a pleasant deep resonance / rumble. I would estimate maybe 5% increase in power and will test mileage on full tank. Had I installed it sooner - would likely have paid for itself.