Works in brooklyn. you get code giving you max 3.05 off per gallon up to 20 gallons. saves you $60 if you max it out. costs you $30-$40 so net is $20-$30 depending on cost and usage
I filled up in NJ a few days ago at $2.47...
Currently gas in Brooklyn is at ~$2.70, so max value is more like ~$54 (unless you use premium...) and you have to find a way to max it out at 20 Gallons (depending on the cars capacity...), but I guess there's still some opportunity to save a few bucks.