This will not protect the whole body of your car though, and it cannot stop corrosion if it has already started, which means it is best applied to brand-new vehicles. The major risk to tar-based solutions is that if not applied properly, cracks may develop in the hardened coating over time and trap moisture within itself, leading to rust.
Heart also offers something called Penetr-Oil, which is a very dense, wax-like oil spray applied to the entire body of the vehicle. There is a catch though, as this method involves drilling holes into a car's doors, fenders, and other areas to make sure the substance gets applied everywhere.
Another known issue is that due to the substance's high viscosity, it cannot get into all the nooks and crannies in the same way more watery oil solutions can. The rust protection most commonly recommended by experts is a drip oil spray, with Known and Rust Check being the leading providers.
As the name suggests, a slight annoyance is that the sprayed oil drips for about two days after application, potentially leaving stains in your garage, driveway or parking spot. Holes still need to be drilled in specific spots on your car to ensure the substance gets applied to all areas and annual reapplication is again recommended.
For those who plan to drive their cars into the ground, rust -proofing could keep your ride looking good for a bit longer. Andrew Tai is CEO of Untangle, which helps consumers find new car deals by providing access to data on what others paid for the same vehicle, current incentives, invoice prices, and more.
Older vehicles were very prone to rust, but new cars have different ways to fight against corrosion and have made massive strides. “ Rust is far less of a concern now,” says Mike Quincy, Automotive Analyst at Consumer Reports.
“The types of metals and treatments have changed over the past 20 years and cars are well protected from rust right from the factory.” Consumer Reports’ reliability data tracks a 10-year history of a vehicle, reporting on issues consumers have with their new cars after 12 months of ownership. Quincy says they actually removed questions about rust from the survey several years ago because the results were showing it wasn’t a factor anymore.
For extra peace of mind, Quincy explains that there are some tips that every driver should consider keeping their car as rust free as possible. Aluminum car parts are less likely to rust than steel, although it isn’t very widely used in mainstream vehicles yet.
“Aluminum isn’t prone to rust since it’s an oxidation of iron,” says Brad Start from Audi. The Audi A8 was the first car on the market with an aluminum chassis, and other automakers, like Mercedes-Benz and Jaguar are also adopting this strategy.
While aluminum construction is mainly for saving weight, the added benefit of long-term reliability is also a great selling point. Carbon fiber is prone to damage and chipping, but won’t rust if exposed to the elements.
“The chemicals used on our roads are far more corrosive than those used in the past,” says Freeman Young, president of Known Rust Control. “Add to this the high humidity and the huge variations in temperature and you have a recipe for rust,” he says.
Young points out that rust proofing also protects other important parts of a vehicle. “Although protecting body panels and vehicle frames against rust is important, the best rust inhibiting products also protect electrical areas such as battery terminals, wiring harnesses, switches and plugs from moisture,” he says.
Rustproofing and undercoating your vehicle can protect it from corrosion and rust. This is especially important for the undercarriage of your vehicle, which commonly comes into contact with substances such as water, chemicals such as salt, and other dirt and debris from the road.
Without some sort of protection, the bottom of your vehicle can rust and corrode, leading to part failure. The best time to rustproof or apply undercoating protection is when you buy a brand-new vehicle that hasn't been driven yet.
This represents the best time to have an undercoating applied, as the under body of the vehicle is probably the cleanest it will ever be. If you only plan on keeping the vehicle for a few years, you might consider sparing the expense and foregoing getting an undercoating applied.
While the underside of the vehicle has already been exposed to water, dirt, and other debris from the road at this point, applying an undercoating now can protect it from further exposure. When having your vehicle rustproofed or an undercoating applied, you have a few options to choose from.
Whether you prefer the latest technology or a more tried and true method, knowing what the different options are should allow you to choose the best one for your vehicle. Using a weak electric current, this small device can stop the corroding effects of rust.
This method involves spraying a tar-based substance on the exposed parts of a vehicle's under body. The tar-like undercoating acts as a barrier once it hardens, keeping out moisture, salt, and other substances.
It also requires expert application, or it can crack, letting in moisture. A wax-like substance applied to the entire body of the vehicle, it hardens once it has dried.
One of the downsides of dripless oil sprays is that you need to have holes drilled into the body of the car at specific points to make it effective. The spray also has a high viscosity, meaning that it does not always get into all the nooks and crannies of your vehicle.
While you could pay someone to apply an undercoating to your vehicle, you can also save money by doing it yourself. After removing any rust, it is time to prime and paint the underside of the vehicle.
The last step in the process requires you to apply an undercoating to the under body of your vehicle. Make sure to apply it to every part that you expect to be exposed to the road.
Allow this coat to dry for at least an hour, or longer if the instructions call for it. A rubberized undercoating is more durable and seals better, protecting the metal from exposure to water.
The statements expressed above are only for informational purposes and should be independently verified. When you shop through retailer links on our site, we may earn affiliate commissions.
Consumer Reports recommends that car buyers skip the undercoating and several other pricey add-ons, including VIN etching, fabric protection, and extended warranties. Editors Note: This article also appeared in the September 2018 issue of Consumer Reports magazine.
| Reader's Digest Skip to main content Photo: Shutterstock Take yourself back a few months: you arrive at your dealership on a cold winter day to pick up the brand new car you bought, but the manager stops you. He suggests rust proofing your vehicle before you leave, and explains that it can be done right at the dealership, for a fee.
We’ve done some research on four of the most common rust proofing methods to make that decision a little easier. Photo: Shutterstock One of the newest and most heavily disputed methods of rust proofing is through an electronic rust protection system.
Often sold by your dealer, an electronic module is a small device that must be professionally installed in your vehicle. These systems emit a weak current through a vehicle’s metal body, theoretically preventing it from reacting with oxygen and corroding.
Photo: Shutterstock Also known as an “undercoating,” tar-based sprays were initially introduced in the 1950s to make car rides quieter. The procedure involves spraying a black, tar-like substance on the floor pans, wheel wells, and other exposed parts of the under body of your car, which then hardens and acts as a permanent shield against moisture, salt, and other elements.
Unfortunately, over time moisture can seep behind the hard outer seal and corrode the metal beneath. Furthermore, the rigid nature of a tar based spray makes it susceptible to cracks, which will pose an entrance for water to get in.
Compared to its tar-based counterpart, a dripless oil spray covers more surface area because it’s applied to more interior regions of the vehicle, but this added protection comes with a price. The application process often involves drilling holes into the frame of the vehicle to maximize the area covered.
Additionally, these sprays will often leave smaller crevices and tight seams on your vehicle unprotected because of their high viscosity. The biggest knock on this method is that the sprayed oil will drip off your vehicle for about two days as it dries.
To make matters even more complicated, it’s become a common practice for manufacturers to use galvanized steel in their vehicles frames. With a coating of zinc, galvanized steel doesn’t react with oxygen the way iron does greatly reduce the risk of rust.
Rust proofing will make more sense if your vehicle is regularly subjected to the elements, but if you plan to mainly do city driving in a warm climate changes are it isn’t necessary. Those with a short-term lease won’t see much benefit in rust proofing, save for a slightly higher residual value.