Is chassis armor useful?
Before we learned in section Functions and differences between chassis pressurization and chassis armor that chassis armor protects vehicle's chassis.
Which car needs chassis sealing or armor?
It mainly depends on whether certain measures have been taken before car leaves factory and how long it can be guaranteed. Most mid to high end vehicles such as BMW, Audi, Buick Excelle, Bora, etc. protect chassis before leaving factory, but when most fuel efficient vehicles leave factory, manufacturers handle chassis very simply due to cost considerations.
Put your hands on chassis of car. If you feel that a layer of plastic has stuck to bottom of car and it is elastic, then it has been protected. If you touch a hard and cold steel plate, then there is no protection.
When inspecting, pay particular attention to whether vehicle's wheel hub, inner side of fender, and connecting steel frame are protected. Although many vehicles are covered with protective paint, it can only be applied topically. These key details are usually overlooked by manufacturer. The protective paint layer applied by some vehicles is very thin, which can only guarantee a limited protective effect in normal climatic and geographical conditions, and may not be fully functional in poor conditions.
Also, check if protective material is a simple asphalt-like material. Asphalt material is dry and hard, has no elasticity and falls off easily, providing very limited chassis protection.
For those who have not done chassis sealing or chassis armor treatment, sooner better, because new car does not need to be polished, and sealing or armor materials can be sprayed immediately after cleaning, and after-treatment effect is also better than car has been in operation for several years, so it is best to do this after buying a car. For vehicles that have been treated in original factory, if they have been in service for about 5 years, consideration should also be given to re-treating armor with an anti-corrosion agent.