FWIW, We were on the road for just over a week and while relocating to another park, we stopped by Walmart in Palm Desert to re-supply the refrigerator. While there it dawned on me that I was due to top off the DEF Tank, so I grabbed a 2 ½ gallon box.
Early the next morning I was working outside the 5th wheel and decided to top off the DEF Tank. Upon opening the Box and Cap I noticed that the seal was broken. I did remember reading on one of the Forums that unscrupulous people are purchasing the DEF and then re-filling with water and returning to the Store, resulting in an expensive trip to the dealership not to mention the down time. After closely inspecting the DEF content I elected to not use the DEF and trashed it. I purchased another brand of DEF (Sinclair?) and noticed that there is no way to open and use the DEF without destroying the package. Check closely and if the Seal is broken do not use.
Early the next morning I was working outside the 5th wheel and decided to top off the DEF Tank. Upon opening the Box and Cap I noticed that the seal was broken. I did remember reading on one of the Forums that unscrupulous people are purchasing the DEF and then re-filling with water and returning to the Store, resulting in an expensive trip to the dealership not to mention the down time. After closely inspecting the DEF content I elected to not use the DEF and trashed it. I purchased another brand of DEF (Sinclair?) and noticed that there is no way to open and use the DEF without destroying the package. Check closely and if the Seal is broken do not use.