First, with any vehicles, you must take a careful look to know what is there... Never go on assumptions.
If this Audi is good, it is good, and if it has been repaired then you must check into that because repairs done properly have good results.
The manner in which the salt was applied, and how the vehicle was kept/maintained does make a big difference.
Here in Minnesota we get to deal with road salt for at least half of the year, and that road salt takes its toll on everything (I wish they would get rid of it myself)
About 10 years ago my city began applying the liquid form of road salt (they use various mixtures depending on the temps of that month because our winters range from 30*F down to -30*F.
The liquid versions have proven to be much more damaging than the crushed solids.... and that stuff flat out kills my grass wherever it sits each year where the old solids only killed grass where it was literally piled.
The liquid version also stick to things much more readily than the solids, and it gets into ANY available opening.
This means if the chassis has holes (which it likely does to facilitate assembly line processes) then liquid salts have gotten into the holes.
Just using my truck floor mat as an example.
Standard Ford carpeted floor mat with solid salts on the road in winter I find a slight whitish remains as the occasional chunk of salt.
With the liquid salt the carpet is totally saturated with the mixture and it is very hard to remove. I literally have to use the pressure washer and a lot of rinsing and scrubbing to get that stuff out of the carpet.
The big thing to look out for with modern cars (2000 and newer) is the hidden rust you can't see because of the poly panels being used so often.
This leads to rust out from the inside out... meaning if you see rust bubbles, or plain rust on the outside, it is likely twice as much rust inside, and once they "bloom" things seem to go fast.
Lok down into the panels, and chassis holes, as best you can to help determine what is going on.
If things look good, even if it was driven in salty conditions, things are likely good... But you have to look for it.
Manufacturers often build to abate this to some extent so look into what AUDI (for that year) was up to.
Sodium Chloride (Rock Salt)
When it comes to de-icing roads, sodium chloride (rock salt) is one of the most common types of salt used.
Rock salt is a naturally occurring mineral mined from underground salt deposits. Rock salt is very effective at melting ice down to about 15 degrees Fahrenheit. However, it isn’t effective at super-low temperatures, so you’ll want another option if it gets colder.
Rock salt is relatively inexpensive and widely available, making it a popular choice for municipalities and transportation departments. Caution is important, though. Rock salt can corrode metal and concrete. Using too much of it can damage the environment by contaminating soil and waterways, and pets and wildlife should be kept away from it.
Sodium chloride is effective and inexpensive but only suitable for some roads.
Calcium Chloride
Calcium chloride is a salt compound composed of calcium and chlorine. It is a white, crystalline solid that is soluble in water and used in various industrial and commercial applications.
Calcium chloride has several advantages. It is used as a de-icing agent to melt snow and ice on roads and sidewalks, making winter driving safer and increasing the hardness of the water. Additionally, calcium chloride is used to preserve food, as it helps to reduce spoilage and extend it’s shelf life.
Magnesium Chloride
Magnesium chloride is a salt compound composed of magnesium and chlorine. It is a colorless or white crystalline solid soluble in water used in various industrial and commercial applications.
One of the primary advantages of magnesium chloride is that it is less corrosive than other types of de-icing salts, such as sodium chloride or calcium chloride. It is also effective at lower temperatures, making it helpful in de-icing sidewalks and driveways. Similarly to rock salt, there can be environmental damage, so it’s essential to use it carefully.
Potassium Acetate
Potassium acetate is a salt compound composed of potassium and acetate ions. It is a white crystalline solid primarily used as a de-icing agent on airport runways and other aviation applications.
One of the primary advantages of potassium acetate is that it is less corrosive than other de-icing salts, such as sodium chloride or calcium chloride, making it a popular choice for use on aircraft surfaces.
Unlike other de-icing agents, potassium acetate is biodegradable and does not harm vegetation or aquatic life. However, it can be more expensive than other de-icing salts and is less effective at lower temperatures, taking longer to melt ice and snow.
Calcium Magnesium Acetate
Calcium magnesium acetate is a salt-free de-icing agent made from calcium carbonate and acetic acid. It is less harmful to the environment than other salts and can be effective at lower temperatures.
Beet Juice
Another option is beet juice, a natural de-icing agent made from sugar beet extract. It is biodegradable, non-corrosive, and does not harm vegetation or aquatic life. However, it can be more expensive than other de-icing agents and may be less effective in extreme weather conditions.
Urea
Urea is a chemical compound commonly used as a fertilizer and a de-icing agent. It is a colorless, odorless solid that dissolves readily in water, making it easy to apply to crops or spread on icy surfaces.
Urea is synthesized commercially using ammonia and carbon dioxide. In addition to its use as a fertilizer and de-icing agent, urea is also used in producing plastics, adhesives, and animal feed.
While urea is generally considered safe, it can have negative environmental impacts if it is over-applied as a fertilizer. Excess urea can cause algal blooms in bodies of water, leading to oxygen depletion and harming aquatic life.
As a de-icing agent, urea is less effective than traditional salts and can be more expensive but is considered a safer and more eco-friendly alternative than the other options mentioned in this blog.
Glycols
Glycols are a class of organic compounds commonly used in aviation applications as a de-icing agent. These compounds have a low freezing point and can remain in a liquid state even in sub-zero temperatures, making them an ideal choice for de-icing airplanes. The most commonly used glycols for de-icing are ethylene glycol and propylene glycol.
While glycols are effective at melting ice and snow, they can adversely affect the environment and human health. Ethylene glycol is toxic and can be harmful if ingested, while propylene glycol is less toxic but can still cause irritation to the skin and eyes.
Additionally, glycols can contribute to water pollution if not properly disposed of. For these reasons, glycols are not typically used as a de-icing agent for roads or sidewalks.
