Do octane boosters really work i have a car that requires premium but it wouldn't it be cheaper to buy regular gas and add octane?

Typically premium gas is only 20cents per gallon more than regular unleaded. so if you put in 15 gallons, you're paying 3.00$ more which happens to be much less than an extra gallon of fuel. fuel additives are not guranteed to boost your octan by 6 pts, and those that are more likely to do it are 15$ a bottle or more. Meaning that premium is not only cheaper, but it will likely provide more performance and better mileage than regular with a fuel additive. take My Pontiac G6 GTP. Factory sticker says it gets 18mpg city. on 87 it gets that 18 mpg which is dismal, on 89 however, it gets 20-21. Which in a basic tank means I can get 300-315 miles out of a tank on 89 vs 270 miles on 87. Take that 315 minus 270 and you get 45 miles further I can drive on 89 than on 87. More importantly that 45 miles translates to 2.5 gallons or 10.00$ extra I'd have to pay using 87 to get the same distance as on 89. The cost of 89 is 1.50$ more pertank granting me a savings of 8.50$ by stepping up a fuel grade. On 91octane fuel I get 23-24 mpg, which by the math shown above saves me 20$ vs going the same distance on 87 and grants me a savings of 17$ after cost. This wont work for every vehicle, smaller engines wont respond as well to the higher octane fuel and give you limited gains over regular grade. But if your vehicle requires premium, you will see similar results. So I'd forget about the hassle of finding the right octane booster and just put in premium 91 octane (or 90 depending on your area) it will save you money and be guaranteed at that octane level. (whereas octane boosters are not)