Compared to 5 other sensors, this tire pressure sensor under-reads between 6-8 PSI. When it gets cold, I always check the tire pressure on my four cars when the temperature drops. When I contacted Jaco Products support using the email address given on the shipping packaging, I quickly received an initial response. I look forward to hearing from you what you intend to do to fix or replace it. I will keep updating. 11/15/18 Alright, here's an update. Same day, same day I'm impressed with the timeliness of their customer service/support which is why I'm upgrading my rating to two stars. They send another tire gauge and said they had to calibrate the first one in their warehouse.