I have an 8 year old Chevy Volt that ran out of refrigerant. Not only is it uncomfortable to drive on a hot day, but the electric vehicle battery cooling system also relies on the AC system for battery cooling in extreme heat. I used the vacuum pump to both confirm the AC system can be recharged (isn't leaking badly enough) and I used it to prepare for the charge. Of course, I used the gauges to perform and confirm my vacuum and charge. I did a video on this if you are interested in learning how to use this set: https://youtu.be/YXoSc2X3a3Y