Why Some Car Owners Are Skipping Silicone Spray on Door Seals This Winter

Many motorists use silicone spray during winter to soften up and lubricate rubber door seals after the first frost, but the most recent information indicates that sometimes such an approach is not appropriate. According to a service bulletin from BMW published by the National Highway Traffic Safety Administration, repairs of door seals should include only proper cleaners and lubricants that will be used according to guidelines; more importantly, it is strongly recommended to avoid the application of any wax or silicone on door seals and door openings.

This information contradicts the general practice that motorists rely on when preparing door seals for cold weather, since the use of silicone is considered an almost universal remedy that will keep the seals in good shape all winter long. However, this recommendation contradicts the statement in the guideline indicating that the state of the seal itself and the door opening should be assessed first of all.

Why some seals should not be coated

According to the BMW Bulletin, the door seal is not only the surface to be treated but may also need repairs or even replacement, depending on its condition. Thus, in some cases, using silicone or wax can prevent the necessary repair process from being performed. This is a significant consideration as in many instances, the application of a substance can worsen the existing problem and make the treatment more complicated.


The reason is that rubber seals undergo constant exposure to movement, dirt, and moisture that can change their performance characteristics. In case there is debris or old residues present on the door seals, using silicone spray can cause trapping these elements or covering them up so that the seal cannot be in contact with the door. The BMW service bulletin posted on NHTSA states otherwise.

The role of proper cleaning

As the bulletin emphasizes time and again, cleaning plays a pivotal role in the maintenance of door seals, implying that one must go beyond the obvious in their efforts. Even if a door seal looks dry and brittle, cleaning may do the trick for you as long as dirt or environmental contamination is the actual cause behind its poor state.

On the surface, this advice may seem paradoxical since silicone sprays are often touted as simple and practical solutions, but scientifically based advice points to different directions. Before opting for silicone spray, one needs to find out the real cause of the poor functioning of their door seals. Otherwise, it would be much better to clean the seal or even replace it.

Safety concerns with silicone spray

Apart from the advantages discussed above, the use of silicone spray poses certain safety concerns that tend to be ignored. Based on the safety data sheet for NAPA Silicone Spray, the product should be classified as an aerosol requiring fire-prevention measures, meaning that one should store the spray away from any source of heat and keep proper ventilation during application.

According to the safety data sheet, in case of a fire, one should take measures to cool down aerosols by spraying the container with water and wear appropriate personal protection equipment, which includes respirators and personal protective equipment. Although the mentioned fire-preventive actions may seem excessive, the need to treat aerosol sprays with caution cannot be underestimated.

This means that while using a silicon spray for maintenance purposes, one has to store the can away from any potential sources of heat and refrain from lighting a flame near the working area, especially in a closed space. In spite of being a household product used for maintenance purposes, silicone spray requires proper handling and storage.

What drivers should do instead?

For vehicle owners facing problems with their door seals in winter, the best strategy would be starting with inspections and following manufacturers' recommendations rather than any general tips. As noted in the BMW bulletin, there is not a single approach that can solve all types of door seal issues, but the repair might require a combination of cleaning, the use of certain products, or replacement.

Thus, if the owner plans to take some action before contacting specialists, they should first inspect the seals and find out whether there is dirt, wear, or any other problem. As mentioned in the BMW service bulletin available at NHTSA, the incorrect use of the products will not allow for performing repairs.

A more careful winter routine

In summary, the message from the service bulletin, as well as the silicone spray safety sheet, is that winter vehicle preparation should be more thoughtful and knowledgeable. Though quick solutions appear convenient, there may be unintended consequences if these solutions do not fit with the needs of the car.

Through proper washing, adherence to manufacturers' recommendations, and safe product handling, motorists will prevent further damage to their cars and ensure optimal performance of their door seals.