My hubby loves this $1/1 any STP Product coupon! Use zip code 62946 and look under automotive to find easier. You will need to watch a short 5 second video to be able to print the coupon.
The STP Gas Treatment and STP Fuel System Cleaner range around $1.87 or $1.97 each at Walmart, so with the coupon you can grab them for less than a $1!
Unfortunately, I am assuming the print limit is one because I was only able to print one per coupon