What you got to remember with the V Power its not just down the octane rating, its the cleaning properties that they put in it. It also lubricates internals and helps protect. I also saw a video where they had normal fuel in a jar with a used engine valve placed in it and the same again with V Power fuel. You couldnt see the valve in the v power jar because it had cleaned all the coke/carbon off the valve. The normal fuel was clean and you could see the dirty valve perfectly in the jar. So you are paying for the extra things they put in it other than just the octane rating, and to be honest with spending money on the booster, you might aswell just buy the v power and save the hassle of mixing it with the fuel and knowing that it is actually doing something, there wont be much difference in cost. As each bottle will only treat a certain amount of litres of fuel, so maybe you could work it out.