I used tuffy liners about two years ago i ended up ditching them, i found the combo of slime and my own liner made up of duct tape has worked better, Im using kenda kwests right now ive put around 400mi on them with no flats and only about a 5-8psi leak a week, my tubes are about a year and a half old so i dont expect much out of them. The problem is though is no tire/liner combo is gonna get you flat proof by any means.