Should I rustproof my new car? What are my options? What to ask my dealer?

Should you buy this service that costs a few hundred dollars? Will it help protect your car and make it last longer?

When you go to a new car dealership, you get offered rustproofing services; you can treat your car even if you’ve had it awhile — you’ve probably seen advertisements.

The arguments you often hear against rustproofing

It’s common to hear that while rustproofing may have been necessary for cars made in the 60s or 70s, that such attention today is pointless, because of improvements to rust protection technology in the manufacturing process. Unfortunately, there are certain cases where these arguments do not make sense.

While there certainly have been improvements, they aren’t necessarily in the area of effectiveness. The application of strict environmental regulations today makes the use of highly effective oil-based and lead-based rust protection technologies impossible for manufacturers to use. Automakers use more environmentally friendly, water-based technologies that tend to be less effective. It’s easy to see proof of this, just by visiting a car junkyard. Cars made in the 60s tend to look far less rusted than cars made after the year 2000.

It doesn’t make sense to rely on anti-rust warranties on new cars, either. These warranties only come into effect when a rust situation goes so far that it causes body perforation.

Road salting can be a challenge, as well. These salts and chemicals can be very corrosive. Road salt is one of the most significant reasons why the Canadian Automobile Association recommends rustproofing.

What kind of options are available?

A number of different rust protection technologies exist, all at different price and reliability levels.

Electronic rust prevention: Rust formation is a chemical process where metal combines with oxygen in the environment. In theory, this chemical process can be slowed down through the application of electrical voltages that make it hard for molecules of oxygen to bond with molecules of metal. It costs about $400 to buy and install such a device. It isn’t considered a particularly reliable technology, however.

Fixed coatings: A thick, protective material is applied to every exposed part of your car’s underbody. It acts as a shield. Coatings based on rubberlike materials, paraffin, or asphalt (the toughest option of all), are available. They cost about $150, and are best applied to new cars, rather than older ones.

Dripless applications: A viscous substance is applied to the underbody, and pumped into specific areas of the inside of the frame as well, through holes drilled. The substance hardens, and offers excellent protection. This treatment costs around $150. Treatment comes with a 10-year warranty.

Drip applications: A more fluid substance is used compared to the material applied with dripless applications. The fluid runs into every part of the frame to offer superior protection. Treatments last one year.

While several well-known brands (such as Krown) do sell DIY rust-protection treatments in spray cans, they aren’t a good idea. It can take patience, equipment and expertise to clean up a car’s underbody well enough to have these substances adhere properly. It can also take experience to ensure that no damage is done, say, by drilling holes in the wrong places or letting coating materials get on rubber seals. Drilling holes on one’s own can void car warranties, as well.

When you find a dealer, ask these questions

Make sure that your car is indeed rust-prone. If it’s an all-aluminum vehicle like the Ford F150, rustproofing may be unnecessary. Once you determine if it’s a good idea, make sure to ask the dealer a few questions.

Ask what parts of car will be treated: It isn’t enough to simply treat the underbody; The person doing the treating should have a plan for existing rust, and for inside areas accessible through holes drilled.

Ask about the warranty: Some rustproofing applications require drilling; in some cases, it may void the warranty on your car if not done by an authorized personnel. The application should come with its own warranty, as well.

Rustproofing your vehicle is a good idea. Allowing rust to gain a foothold in your car can have unacceptable consequences.