I must admit that my old jet reading seat of the pants tuning was WAY off before the wide band. I burned up hundreds of gallons in fuel, killed plugs and wore out my motors "guessing" about which direction to go. Prime example; my new combo...........WAY more power, completely blowing my tires off on my first pass(never before)and my afr`s were close on the street then we adjusted at the track although I have other carb related issues which we`ll figure out. Many ways to skin a cat and better tuners than myself can probably get by w/out one but not me and how many times do we read on here about someone hitting the track after a new motor or combo that runs SLOWER till they go back and try it again. My first time out on 3 year old tires and still got a new promising best w/WAY more to come. Not just the wide band but others watching how the car leaves and making the necessary changes to the suspension helps also...........