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Corrosion, oxidation and rust all mean the same thing — water, salt and pollutants are dissolving your vehicle. (Fred Lum/Fred Lum/The Globe and Mail)
Corrosion, oxidation and rust all mean the same thing — water, salt and pollutants are dissolving your vehicle. (Fred Lum/Fred Lum/The Globe and Mail)

Driving concern

Do I need to install an electronic rust inhibitor? Add to ...

I just bought a new Tucson and wondered if it's necessary to have an electronic rust inhibitor installed? The dealership recommends the gadget, but I was wondering what your take would be. – Mario, Kelowna, B.C.

Electronic rust protectors will eat a hole through your wallet and probably won't protect your vehicle any more than it's protected already, according to the Automobile Protection Association.

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Dealers charge as much as $800 for the quickly-installed device — a small box that applies a weak electric current to the metal on your vehicle — which normally retails for as low as $150, says APA president George Iny.

The consumer watchdog doesn't recommend the devices, which are based on the concept of cathodic protection used on the submerged parts of bridges and boat motors.

Those devices only work when the metal is submerged in water. While device manufacturers have plenty of anecdotal evidence from satisfied customers, Iny says he's seen no studies showing electronic rust inhibitors actually protect your car on the road.

“Your car's not usually underwater,” Iny says. “I'd like to see a technical report signed by a Canadian engineer that shows the device is effective.”

The word theory gets used a lot on brochures for these gadgets, but, other than comments on various Internet discussion boards, there's no research showing that a vehicle equipped with the device had less corrosion than it would have had anyway, Iny said.

Corrosion, oxidation and rust all mean the same thing — water, salt and pollutants are dissolving your vehicle. Rust is iron-oxide and it is caused by a chemical reaction between oxygen and iron when exposed to water. The oxygen steals electrons from the iron and the iron slowly disappears, producing rust. This corrosion happens with most metals and gets sped up when water combines with carbon dioxide, the chemicals in acid rain and road salt.

Iron is the man ingredient in the steel used to build your car – and, as anyone who has ever owned a car built before the mid-1980s can tell you, steel rusts.

To prevent that, car builders now use galvanized steel. That means the steel is coated with zinc. The zinc dissolves instead of the steel, keeping the steel safe, until the zinc dissolves away.

On top of this, car makers use layers of paint — a primer, a colour layer and a clear coat — as a barrier between the galvanized steel and water and pollutants. Plus, they spray a rubberized protective coating on the underside of the vehicle.

“The paint plus zinc combination is typically designed for a minimum life of ten years, assuming no major damage,” says McMaster University engineering professor Joseph McDermid. “That's why manufacturers are now able to offer warranties. Electronic protection shouldn't be necessary and I wouldn't recommend it.”

Instead of pricey dealer rustproofing gadgets or sprays for new vehicles, spring for mud flaps to protect from damage from rocks and make sure all chips or scratches in the paint are fixed quickly, McDermid says.

Hyundai Canada spokesman Chad Heard says Hyundai dealers are independently operated businesses and are free to “offer value-added services to their customers.”

But, Heard adds, “Hyundai vehicles come from the factory with rust prevention coating and additional aftermarket electronic rust prevention is not required.”

If you have any driving queries for Jason, send him a message at globedrive@globeandmail.com.

Follow us on Twitter: @Globe_Drive

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