Preventing Rust and Corrosion on Your Electric Vehicle

By Isabella Storyclaire

last updated September 17, 2024

Contributions sourced from

Are Electric Cars More Prone To Rust?

Today, few cars on the road are plagued by rust. The vehicles that are rusted are generally more than a decade old. However, in recent years, there have been many reports that electric cars are more prone to rust than gas-powered counterparts.

Electric vehicles (EVs) are more prone to corrosion. In part, this is due to a shift towards partial galvanizing. The use of lightweight materials like aluminum also contributes to this. Specific metal pairings are also known to promote oxidation and corrosion.

If youre worried that your electric vehicle is more susceptible to rust, we will tell you everything you need to know. Well explain why EVs rust more quickly, how to prevent rust formation, and whether electric cars can be rustproofed.

Do Electric Vehicles Rust More Than Other Vehicles?

Over the decades, the automotive industry has made strides to reduce the corrosion of vehicles. However, there have been reports of increasing rust issues with two types of cars in recent years. This issue is primarily attributed to the widespread galvanization of car bodies.

In 2020, 6.7 million cars were inspected as part of a study. Out of all the vehicles inspected, 441,000 had rust issues. The vast majority of cars that displayed these issues were older than ten years. However, a small percentage of those vehicles were also newer electric cars.

Due to this, many consumers have wondered whether EVs are more prone to rust than other new cars on the road today. Unfortunately, this appears to be the case. Many car websites have described Teslas Model 3 EV as the perfect corrosion candidate.

This was primarily confirmed by Ralf Roessler, a rust expert who examined a Tesla vehicle with less than 200 miles on the odometer. The frame, which only received a light coat of paint, showed signs of rust. Roessler stated that this rust would turn brown within six months and would be rusted entirely in six years if untreated.

Rust was also observed on the suspensions connecting rods. Many EV owners have also reported rusted bolts and disc brakes. However, you might be wondering why electric cars are more prone to corrosion let us explain!

Why Are Electric Cars Prone To Corrosion?

Many recent studies and reports have confirmed that electric cars are more likely to rust than other cars on the road. However, many EV owners are unsure why their cars are prone to corrosion. Ultimately, this comes down to a shift in manufacturing processes.

When a rust expert evaluated a relatively new Tesla, he noted that only a thin layer of paint was provided. In many ways, this speaks to why EVs are rusting faster. One aspect of this is manufacturers moving towards partial galvanizing, which offers less protection against rust.

Due to the weight of electric car batteries, many manufacturers are using lighter materials, such as aluminum and magnesium. Unfortunately, these lightweight materials can react, resulting in the formation of galvanic rust.

Ill material pairings can further exacerbate the corrosion of electric cars. When these pairings are in hidden locations of an automobile, corrosion spots can start forming. However, due to the hidden area, this type of rust will go unnoticed longer by owners.

When you combine these reasons, it becomes apparent why electric cars are more prone to corrosion. At least there are various ways to prevent and combat rust regarding EVs! Well look at this in the following sections!

Preventing Rust On Electric Vehicles

As discussed earlier, many electric cars are more prone to rust than their gasoline-powered counterparts. However, being aware of this issue allows EV owners to implement ways to prevent their vehicles from rusting.

Many substances can damage your vehicle over time, including oil and road salt. These substances mainly affect the undercarriages of EVs. To prevent these unwanted materials from damaging your car, you need to wash your vehicle regularly.

Overall, regularly washing your electric vehicle is the best way to prevent rust and oxidation. Youll need to ensure that a thorough wash is done. EV owners will need to pay special attention to aspects like their undercarriage and wheel wells. You might want to take your car to a car wash to ensure a good job is done!

In addition to washing your car, its essential to keep an eye on your paint job. Paint helps protect vehicles from rusting. When you notice paint chipping, rust will begin to form. When your cars paint starts chipping like this, its essential to touch it up.

By following these simple EV maintenance tips, you can actively prevent rust from forming on our EV. All you need to do is regularly wash your electric vehicle and routinely inspect it for signs of rust!

Can You Rust-Proof An Electric Car?

With gas-powered vehicles, rustproofing is a simple way to prevent rust in the long term. Many EV owners have wondered whether they can rustproof their EVs in the same manner. The answer is yes and no.

Yes, electric cars can be rustproofed. In fact, you can even rustproof a Tesla Model 3. Electric or not, most cars are made from steel and require rustproofing, which is done by applying an anti-rust treatment. Unfortunately, its not as simple as applying it to your vehicle yourself.

With gas-powered vehicles, applying an anti-rust agent is easy and can be done at home. However, many electrical components can be damaged by applying one of these rustproofing products. Thats why its not recommended EV owners rustproof their vehicles themselves.

It is recommended that EV owners hire a rustproofing specialist. These professionals will be able to use the best treatment for your car and theyll know exactly how to apply it.

Conclusion

When compared to gas-powered cars, electric cars are more susceptible to rust. A shift towards partial galvanizing is partly to blame for this. Certain light metals and ill-pairings can also contribute to the formation of rust on electric vehicles. Luckily, this can be prevented through regular washes and rustproofing.

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Should you rust proof your car in Canada?

About 5 million tonnes of road salts are used in Canada each yearto prevent snow and ice from accumulating on roads and make driving safer. Ontario, Quebec and the Atlantic provinces are particularly heavy users.

However, safer winter driving comes at a cost.

It can cause corrosion damage to vehicles especially brake linings, frames, and bumpers as well as roads, bridges, and underground utilities.

There are also environmental concerns road salts, including sodium chloride (NaCl), calcium chloride (CaCl₂), potassium chloride (KCl) and magnesium chloride (MgCl₂) are monitored substances on Environment and Climate Change Canadas Priority Substances List (PSL).

There are less toxic and less corrosive alternatives such as beet and cheese brine, but salt is the cheapest and least-smelly option, so continues to be widely used.

What causes a car to rust?

Rust is the corrosion of iron (steel contains iron) as it reacts with moisture and oxygen in a process called oxidation, which weakens and breaks down the iron into a flaky powder, causing holes to develop.

The electrochemical reaction is accelerated by higher temperatures and the presence of salt, so the spring months when the humidity is higher and the weather is warmer, are the perfect environment for rusting particularly if there is grime and salt residue left on the underside of your car.

As per my Hyundai Elantras owners manual:

Corrosive materials used for ice and snow removal and dust control may collect on the underbody. If these materials are not removed, accelerated rusting can occur on underbody parts such as the fuel lines, frame, floor pan and exhaust system, even though they have been treated with rust protection.
Hyundai Elantra: Exterior Care

Now, the exteriors of modern cars have multiple coating layers that protect the bare metal and prevent it from rusting as long as they are kept intact:

Modern cars metal frames (chassis) are first dipped into a large bath (see video) to be completely and consistently coated with zinc phosphate primer through a process called electrodeposition (also called electro-coat or e-coat primer). This coating acts as barrier that provides complete coverage and consistent thickness, preventing oxygen and moisture from getting to the metal body.

The colored basecoat and acrylic polyurethaneenamel clear coat (paint without the pigment to give it colour) are then applied, followed by a wax coat to act as a sacrificial layer prevent grime and stains from sticking to the clear coat.

Manufacturers also add plenty of drainage holes along the doors and rocker panels to let the inside of the panels dry out.

If the barrier is rubbed, chipped, dented or cracked off by wear-and-tear or accidents and exposes the bare metal, the car will start to rust. In addition to road salt, dust control chemicals (calcium chloride), acid rain, road tar, insects, ocean air and industrial pollution can also accelerate corrosion.

Rust typically starts:

Along the bottom of seams and joints on the inside of vehicles body panels. Salty water can trickle in past rubber seals, accumulate if the drainage holes become blocked by debris and start rusting from the inside out. The panel seam rust coming from the inside is the big problem, not rust from surface chips. No amount of washing will prevent this.
Underneath the car where rocks and debris damages the protective coating and moisture-soaked dirt and salt deposits build up. Mud is particularly corrosive because it is slow to dry and holds moisture in contact with the vehicle. This also applies to visible surfaces, but especially to the underside of the vehicle.
Surface where scratches, dings and nicks caused by rocks, or scrapes and dents cased by accidents that break the protective coatings and paint particularly on the hood and doors. These are easier to spot, and if found early, to treat and fix.

Here are some examples of how rust has affected vehicles in the past:

1995 to 2000 model year Toyota Tacoma trucks were bought back in the US due to rusted out frames that were not coated correctly
In 2015, 3,000 BMWs were recalled after being exposed to water and salt in Halifax
2008 or earlier model years In 2015, the US National Highway Traffic Safety Administration found that road salt was causing thousands of vehicle brake failures after a 4 year investigation.

What is rust proofing?

Rust proofing is the prevention or delay of the rusting of iron or steel, achieved for cars through the application of an anti-corrosion protective coating on the surface of the metal.

What are the benefits of rust proofing?

Keeping your vehicle rust-free will lead to a:

Longer lifespan
Lower repair expenses
Higher resale/trade-in value
Lower environmental impact

Should I rust proof my car?

Whether or not you should rust proof your car depends on where you live, how long you intend to keep the vehicle and how much other preventative maintenance you do:

Its probably worth it if you plan to:

Keep the vehicle for a period beyond the manufacturers rust warranty, and especially if you plan to drive it into the ground
Rarely, if ever wash your car during the winter or wax it semi-regularly
Drive often in the winter months
Drive in an area that uses a lot of road salt in the winter
The cost of rust proofing is low compared to the value of the car (car is new, luxury, collectible or sentimental)
Ignore small chips and scrapes

Its probably NOT worth it if you plan to:

Return/trade-in the car at the end of its lease
Sell it before the new vehicle corrosion warranty runs out
Wash your vehicle after every snowstorm
Drive infrequently, and less in the winter months
Drive in an area that primarily uses sand in the winter
The cost of rust proofing is high compared to the value of the car (car is new, luxury, collectible or sentimental)
Fix all chips and scrapes immediately

How much salt does your area use in the winter?

Check your areas winter road clearing or salt management plan to find out how much salt they use. It depends on:

Road salt is used more in urban areas than rural areas. Salt is not appropriate for use on the gravel roads as it will create potholes, so sand is used instead.
Cities near bodies of water with milder winters and greater precipitation like Montreal (about 200,000 tonnes), Ottawa (185,000 tonnes), Toronto and Halifax use the most salt.
Road salt starts to lose effectiveness at -10C and is ineffective below -20C. In the prairies where winters are colder, its often too cold for salt to work. Regina, SK typically uses a mixture of 94% sand and 6% salt and Calgary will use a sanding chip mixture of 97% fine gravel and 3% salt when road surfaces are below -10C.

How long do you plan to keep the vehicle?

Will the cost of applying it every year (~$150) over the course of the time you keep the car be offset

Car manufacturers typically offer 5 year, unlimited km corrosion warranties on new cars that cover rust holes in the metal body panels from the lower window line down under normal use and maintenance, including Hyundai, Toyota, Ford and Honda. Volkswagen offers 7 year/unlimited km.

For surface corrosion (no hole), the coverage is slightly shorter: Honda covers for 3 years/unlimited, Hyundai and Ford 3 years/60,000 km.

However, most modern vehicles do not show visible signs of rusting until they areover 5 or 6 years old according to the APA just as the warranties are expiring. The average life expectancy of a vehicle in Canada is 12.88 years and used cars are retaining more of their value and prices are hitting record highs, so maintaining the vehicle you own is becoming even cheaper than buying another car that it already was.

I would think that between when the new car warranty ends and the average life expectancy of the vehicle is when rust proofing is most worth it the car is still relatively new and valuable and it will stop rust from spreading any further.

How much maintenance will you do?

Washing off salt and grime Unless youre planning to wash your car after every snowstorm, theres a good chance that youll have to drive on some really messy roads, then leave your vehicle to sit in temperatures above freezing the next day. Or worse, park it in a heated garage while its still wet.

Repairing minor rust damage Most rust starts as minor cosmetic damage on its surface and along the bottom of vehicles body panels which only affects the appearance of the vehicle. Small holes are generally cheap and easy to repair if dealt with early by filling them with epoxy putty, sanding it, and painting it with a layer of primer, base coat (colour) and clear coat. However, if left to fester, particularly in the vehicles frame, it can turn into a safety concern.

Personally, Id rather spend $150 every year than pay $15 for a car wash every week or two during the winter or try to squeeze under my car to hose it off myself. If youre able to hoist your car up in the air and pressure wash your entire undercarriage after every winter storm, then all the power to you!

Can you rust proof an aluminum vehicle?

Yes, a vehicle with an aluminum frame or body can be rust proofed, but the value of doing so is somewhat reduced since aluminum corrosion is typically only surface-level and is more cosmetic, than structural in nature when compared to iron rusting. This thin layer of white oxide film forms on the surface and protects the material underneath from further corrosion.

That said, most vehicles that have an aluminum body still have a steel frame, suspension, and other components eg. 2021 Ford F-150) that can be protected with rust proofing. Aluminum is considerably more expensive than steel, so typically only higher-end vehicles such as Tesla Model S, X and Audi A8 are primarily made of aluminum.

When combined with water, the chlorides in common salt (sodium chloride) and acids contained in dirt can penetrate the aluminum oxide film and cause pitting on the surface, producing a white powdery corrosion.

Can you rust proof a hybrid or electric vehicle?

Yes, hybrid and electric vehicles can be safely rust proofed by a qualified technician. Vehicles all have differences that must be taken into account particularly to ensure the drilling doesnt hit any wires and the biggest service providers will have details about how and where to treat them.

Manufacturers do not recommend it and many specifically state it shouldnt be applied, claiming that coating the electronics, battery, electric motor, and high-voltage electrical wiring will cause damage.

However, many hybrids and EVs include plenty of steel, which of course can rust. The Hyundai Ioniq uses high-strength steel for the structure and aluminum for non-structural panels.

Krowns formula, for example, has a high dielectric strength, meaning it does not conduct electricity and will not short the electrical systems.

Does rust proofing or drilling holes void manufacturers warranties?

No, a professionally applied rust protection such as Rust Check, Krown or Corrosion Free will not void the manufacturers corrosion/perforation warranty, including the drilling of holes. However, they may have a case not to cover you if the damage was done due to improper application or drilling.

Car dealers may say that itll void your warranty as a scare tactic to get you to buy expensive and ineffective tar undercoating and electronic rust inhibitor modules from them as well as otherpricey add-ons, including VIN etching, fabric protection, andextended warranties.

In Canada, modifying your car or installing aftermarket components will not void your cars warranty, unless the modification causes damage to or breaks other parts in which case your claim can be denied.

What about the holes drilled?

Inconspicuous access holes are drilled in the door jambs, rockers, etc. so they can snake the spray wand in and spray the solution around the inside of the panels:

This is where salty water can trickle in past rubber window seals and accumulate if the drainage holes become blocked by debris:

The holes are then greased to protect the exposed metal from corrosion and plugged to prevent water and air from entering:

In an ideal world, all of the panels on the car would be removed to get access to the interiors portions of the vehicle instead of drilling holes. However, the time it takes to do this would increase the cost of the service by hundreds of dollars. Drilling holes is faster and cheaper.

If youre still concerned, you always have the option to opt out of having holes drilled, but protection wont be as complete.

Is rust covered by car insurance?

No, car insurance policies do not typically cover damage to your vehicle caused by the normal wear and tear of operating it, including rust and corrosion.

Can you rust proof a used car that already has rust?

Yes, you can rust proof a vehicle if it has already started rusting. It will seep into the rust and push out moisture, slowing down its progress.

Krown states it is absorbed into existing corrosion and pushes out any moisture, thus slowing any further corrosion down significantly.
Rust Check states that while it will not repair damage already done to older vehicles but it will inhibit the progression of rust in problem areas.

When should I rust proof my car?

The best time of year to rust proof is in the spring. This is when the humidity is higher and the weather is warmer, creating the perfect environment for rust, particularly if there is grime and salt residue left on the underside of your car.

If your vehicle has never been protected, then the best time to spray it is right now. If you want the service providers warranty coverage, your car must be rust free, recently purchased and less than a few model years old.

How often do I need to rust proof my vehicle?

Rust proofing companies recommend getting the service done annually, and it must be done that frequently in order to maintain their warranties.

The spray slowly dissipates over time and eventually the metal will once again be exposed to the elements. It will wear away faster in high spray areas such as wheel wells and the bottom of rocker panels.

However, a vehicle in a benign environment (eg. Trenton, ON) needs application far less frequently than one exposed to a severe environment (eg. Montreal, QC) according to a2006 studyconducted by the Department of Defense Research and Development to review corrosion control and prevention on army vehicles.

Depending on your driving habits, what kind of roads you drive on, and the climate, you can determine if you should do it every year, or every 2. Every 2 years is much better than not doing it at all.

Can you do rust proofing yourself?

Yes, you can buy aerosol cans of one of the top products and apply solution directly to areas where you see rust has started or to touch-up a previous application:

You can also get a spray gun from Canadian manufacturer Lemmer on Amazon and follow Canadian YouTuber 4DIYers excellent video to apply any of the following yourself:

However, a professional service will likely be quicker and more precise, and prevent any from getting where it shouldnt, such as on the brakes, exhaust and drive belts.

How to prevent my car from rusting?

The best ways to prevent your car from rusting are to:

Remove stains insects, road tar, tree sap, bird droppings, industrial pollution and similar deposits can damage your vehicles finish if not removed immediately. Bird droppings are especially corrosive and may damage painted surfaces in just a few hours.
Repair scratches and chips Touch up deep scratches and stone chips as soon as you notice them to reduce the spread of corrosion. Minor issues are cheap and easy to fix if repaired promptly, while exposed metal will rust can develop into a major repair expense. You can do this yourself, or if its a big job, contact a reputable professional to help you. See touch up paint pens at Canadian Tire and Amazon
Wash your car regularly, including underneath In the winter, aim to wash the underside of your car at least once a month. Doing this will help extend the life of the protective coating which protects your car from rust. In more severe environments, wash as often as once every 2 weeks. Clean the underside thoroughly when winter is over.Use a pressure washer to ensure that mud and road grime is actually removed and not just wetted, which would accelerate corrosion. Be thorough and pay special attention to the components under the fenders and those that are hidden from view.
Wax your car Protects the clear coat layer from surface scratches, UV exposure, bird droppings, hard water and acid rain.
Keep your garage dry Dont park your car in a damp, warm, poorly ventilated garage as that accelerates corrosion. If the vehicle is still wet from washing or covered with snow, ice or mud, leave it outside to dry first or leave the garage door open for a while to let everything dry out.
Inspect and clear drainage holes Make sure the drain holes in the lower edges of the doors and rocker panels (below the doors) are kept open and clean so that moisture can escape and water cant collect.