I just used some b-12 in my car, just follow the directions

I think I was around 1/2 tank, might work a bit better if you are near empty then fill up right after putting it into the tank

- 95 Mystique LS - Zetec/5spd - 99 Contour SeVT Sport - Duratec/5spd Official NE-CEG Contour/Mustang Family