Freed my camber bolts on the back of my vectra c. Tried other penetrants with no luck. I couldn't use heat or I would have damaged a none replaceable bush. Sprayed once I the morning the again around 5pm all the bolts came loose. It does do what it says it does. I have no idea if I had to leave it that long but as with everything rusted in time can only help. The best thing about this product is its rubber safe and does the job as advertised.