They sell it at most paint stores, I mix it very sparingly to a full tank, which in my Legacy is around 12 gal. I researsed the ratio's but can't remember what it was, so I just add a small ammount. Maybe I'll find the exact mixing percentage on our snow day. I wouldn't use a lot of it because I'm weary of it being detrimental to the motor, and it doesn't lubricate like traditonal gasoilne. Fuel these days, flat out sucks, with all the detergents and ethanol, it's the most limp wristed crap ever. I'm trying to create some real explosive jungle juice.