I am requesting that the dot NHTSA look into the possibility of a tire defect that can affect the safe operation of vehicles with cooper discoverer srx tires. I purchased a set of 4 cooper discoverer srx tires and had them professionally installed on my 2013 Ford Explorer. The size is 255/50R20. During the winter of 2018-19 they began to leak air excessively when it was cold. The loss would grow to a point the low air light came on every week. It was various tires causing the issue. This continued throughout the winter and into the spring of 2019. The leaks are more severe when driving than when the vehicle is stationary. I believe the tires may have been compromised to the point that they are continuing to leak when it is warm outside now. Over the past 3 months I have had them in 2 separate times and have been told the tires do not have a hole in them nor leak at the bead but are leaking due to weather or other. I have made multiple attempts with cooper tires to handle the safety issue and they not handled their warranty matter. I have been to two separate dealers who sent me back to the original installer and they have had them off two times to verify the issue. Before this safety issue becomes a serious incident I would like to see the tires investigated or possibly recalled. I am concerned about the safety of these tires and believe the model may reduce safety as they age. Mine are 2 years old almost. Thank you,

- Bemidji, MN, USA