I've been using additives for about 20 years. Originally to prevent gelling, clean injectors, and later to add lubrication. I always saved the smaller bottles (32 ounce) then once I had a bunch of them, I would refill from half gallon jugs or gallon jugs or whatever size jug came in the case of additive I bought. It was messy trying to pour from a large jug into a skinny funnel into smaller bottles. It also was not to easy to see the amount inside the bottle and overall not really accurate. I see people that try to save 5 cents a gallon on fuel, but dump in additives without measuring, wasting dollars per gallon. This dispensing pump works really well, is very smooth to operate, and EASY TO USE. I refill my bottles and always have the right amount. I put enough in each bottle to treat 1/2 tank(typical fill-up for me, but with this you can easily dose to your typical fill-up). If it's really cold and I want to double dose, then I can add 2 refilled bottles. Great product. Great idea. Great job Opti-Lube. I would give 10 stars if I could.