I typically buy Boost Juice and then mix it 50/50 with Denatured alky. Denatured alky is basically 100% meth so this give me about a 75/25 mix and the car really likes it. This also give me a better bang for the buck.
45 Boost Juice
30 Denatured Alky
75 for 8 gallons of 75% meth