I put this in my tank mixing it in the half way point on a fill up. took a spin and wow what a difference. Your ecu automatically adjust your timing for the extra octane. 1 bottle treats 25 gallons, its a 15 oz bottle so our tanks will take 10 oz's. It costs $10 a bottle off the shelf, but if you buy a 12 pack from amazon its only $6 a bottle. This stuff is cheaper then torco and will help prevent problems associated with getting a bad load of gas. Its a no brainer to me! Now go get some!