Two common treatment options for handling rust problems on automobiles are undercoating and rust protection. Though these two treatments are similar in some ways, they offer two different levels of rust prevention, either of which may be better for a particular driver depending on a variety of factors.

Below is an explanation of what each of the two treatments are, as well as some advantages of each option:

Car undercoating

Undercoating consists of applying a rubberized protective spray only on the underside of the car. While this protects some of the vehicle's most vital parts from rust problems that could lead to mechanical failure, it does not offer protection for other parts of the automobile body like the doors, hood, and roof. 

Advantages of car undercoating

  • Protects the most important mechanical parts of the car
  • Seals against harsh chemicals and abrasion that the vehicle can be exposed to from debris on roadways
  • Usually more economical than complete rust protection because it involves less labor

Rust protection

Rust protection is undercoating spray that is also applied to both the underside of the car and the rest of the automobile body. Rust protection will protect not only the car's underside, but also doors, fenders, upper body, tailgates, and more. 

Advantages of rust protection

  • Offers comprehensive rust protection
  • Protects not only mechanical components, but also the car's overall appearance from rust development

Which is better for your vehicle?

Factors influencing whether undercoating or rust protection is better for a particular driver include the driver's geographic location and how the vehicle is going to be driven. Undercoating is generally understood to be a more limited form of rust prevention than rust protection.

Undercoating is therefore more appropriate to geographic locations where exposure to severe winter weather conditions and road salt is less likely. Car undercoating might also be sufficient if drivers are not going to be driving a vehicle many miles per week or on a daily basis. It will offer more than enough rust prevention for a vehicle that is garaged most of the time and only taken out in optimal whether conditions. 

On the other hand, a vehicle that is a driver's regular commuter vehicle will probably experience more severe rust risk. This is especially the case if the vehicle will be driven in a colder area of the country where winter storms and rock salt treatment on roadways are common. For these conditions, drivers might want to invest a little more in a rust protection treatment to keep their car rust-free.