I've been using FP60 and FP60+ for quite some time. We moved in April and I moved all my FP60+ stuff and it all got buried in the garage. I finally dug it all out after months of being behind other boxes to find both of my FP measuring bottles have collapsed inward. One so bad that it split in one spot (so I have leakage).. The other collapsed inward and squeezed some product out the top. The product sat on the bottle for months. Now the outside of the bottle is tacky and the wording on the bottle (along with the measurement intervals) just wipe away with a rag. Why these caps aren't self venting I don't know. But I think I'll go back to FP60 so I don't have this problem again. Even Ritchie from Lube Control admitted this was a bit of a problem and switched to higher density gallon bottles to help combat this. Then again, I may just forego fuel cleaner all together as both of our cars are GDI now.