What Metal Are Vehicle Exhaust Pipes Made Of? (Answered)

Stainless steel, cast iron, and aluminum compounds are the most popular metals used to make exhaust pipes

Why is stainless steel the most popular metal used to make exhaust pipes? Why is aluminum not the best choice for exhaust systems? We’ll give you all these answers and more, so keep reading! 

Here’s What A Vehicle Exhaust Pipe Is Made Of 

Most vehicle exhaust pipes are made from stainless steel. This is chosen primarily for its capacity to resist wear and rust. Car exhaust has several highly corrosive and toxic compounds and water, easily eroding certain metals. 

Car vehicle exhaust pipe
Car exhaust tailpipe made of stainless steel material.

Most exhaust pipe materials are typically simplified as a form of “stainless steel.” However, the reality is most exhaust pipes have multiple metal compounds, including the following: 

  • Galvanized Steel 
  • Stainless steel
  • Aluminum
  • Cast iron
  • Iron

These materials are used to save costs and prevent decomposition. 

However, many of these compounds are lumped together as ferrous alloys. Ferrous alloys are metals made primarily from iron and carbon. It’s a strong, rust-resistant, and affordable material, making it ideal for exhaust pipes. 

Aluminum is a common compound in the metal used to make exhaust pipes. However, it’s not usually one of the main compounds. This is because aluminum loses its molecular integrity at high heat temperatures. 

Exhaust systems easily exceed 400 degrees Fahrenheit, with some exceeding 1,000 degrees. 

This makes aluminum and other light metals ineffective and potentially dangerous for such construction. Therefore, most exhaust pipes are made from stainless steel compounded with other materials. 


What Is The Best Metal For Exhaust Pipes? 

Car exhaust system with engine connections
Car exhaust system with engine connections.

Stainless steel is the best metal for exhaust pipes. It is highly resistant to environmental degradation, rust, and other damage. It’s also lighter than metals such as cast iron and cheaper than metals such as titanium. 

Cast iron was invented back in 1913. It was created by combining iron with chromium to increase the strength of the metal without drastically increasing its weight. 

Chromium has a lustrous appearance with high resistance to corrosion and decay. Unlike metals such as iron and zinc, which have a high corrosion level, chromium is very resistant to oxidation and corrosion. 

It’s also one of the hardest substances, according to Moh’s Hardness Scale.

With a rating of 8.5, it’s right behind the other two hardest substances, boron (9.5) and diamond (10). This means few things can cut or damage this metal, making it the perfect material to prevent damage and corrosion. 

Weight is a primary consideration when selecting car materials. The more weight the car must haul around, the more fuel it wastes, which is why stainless steel is so important. 

Recent estimates indicate that car weight greatly impacts car energy performance.

Decreasing the weight of a car by 10% can decrease fuel consumption by 6-8%, which is significant over time. 

Is There a Difference Between Diesel and Gasoline Exhaust System Metal Components? 

Both gasoline and diesel fuel vehicles usually use stainless steel. Gasoline vehicles use a variety of 300 series stainless steel, but 304 is the most popular. Most diesel vehicles use 409 stainless steel, a highly resistant type of stainless steel. 

409 stainless steel is the best option for diesel vehicles. This metal is considered stainless steel but has more components than regular stainless steel. 

Some of these components include expensive metals such as titanium. This metal is very expensive, which is why it’s not used in all car exhaust systems. 

Most gasoline engines are made with 304 stainless steel. This form of stainless steel is more similar to the traditional type, except it also has nickel. 

While 304 stainless steel is very resistant, it’s not as strong and heat-resistant as 409 stainless steel. 

Some other less common and out-of-date metals include cast iron, galvanized steel, and cold-rolled steel. These metals are good but not as durable and heat-resistant as stainless steel. 

How To Avoid Exhaust Pipe Corrosion?

Underneath the car with engine and exhaust system
Underneath the car with engine and exhaust system

Routinely cleaning and washing your exhaust system is a great way to prevent corrosion. This removed heavy materials and dirt from the bottom of the car, which may induce rust and decay. You should also invest in a higher-quality exhaust system so it’s less likely to decay and lasts longer. 

Some of the best ways to prevent corrosion and decay on your exhaust system include the following: 

  • Regular cleaning of the bottom of your car
  • Consider painting or undercoating your car’s undersides 
  • Wax
  • Drive for longer than 20 minutes 

Cleaning your car’s exhaust system is the number one way to prevent rust and decay. Spraying it with a hose and wiping off dirt and grease to prevent corrosion and rust. When particles cling to the metal, they hold contaminants and moisture, which can react with the exhaust system. 

Do not wax the exhaust system. But regular waxing of your car is a great way to prevent water and moisture from sticking to your car. 

Drive for longer than 20 minutes (typically, 30 minutes is recommended at minimum). This helps the system warm up and burn off excess water and moisture particles. 

Can You Use Mild Steel For Exhaust Pipes? 

You can use mild steel for exhaust pipes. Many replacement pipes and cheap exhaust systems are made with mild steel. However, you should not use this metal since it’s not rust and corrosion-resistant. 

Mild steel is used in exhaust systems, but it’s not the best option for these systems. Mild steel is made by combining iron and carbon. It’s very cheap and thus very popular in building. 

However, this metal doesn’t have the added chromium, making it rust-resistant. However, it is commonly used in replacement parts for an exhaust system. 

The primary reason for this is its affordability. While these might only last a few years, they make for a cheap way to keep your car running a little longer. 

What Are Factory Exhaust Pipes Made Of? 

Exhaust pipes can be made of various metals, depending on the manufacturer. However, most exhaust systems and pipes are made of stainless steel. But they can also be made with cast iron, aluminum components, and other metals. 

Exhaust pipes from car manufacturers are usually made of stainless steel. These pipes are usually reliable and last for a long time. 

Some replacement parts can be made with cheaper and less durable metals. Metals such as cast iron are common but unnecessarily heavy and rust easily. Therefore, you should check the tailpipe if you’re buying a used vehicle. 

They may have replaced the older pipe with a new, cheaper variety that might only last a year or so. 

How Long Do Exhaust Pipes Last?

Most exhaust systems can last several years. The exhaust pipes are usually the first thing to go on your car’s exhaust system. If driven at an average mileage each year and properly cared for, your exhaust pipe can last between 2-3 years. 

Most exhaust pipes start corroding on the inside first. This is where most of the moisture gathers and eats away at the exterior parts of your car’s exhaust pipe. 

Several things can impact the life of your exhaust pipe, including the following: 

  • Corrosion from oil and gas 
  • Environmental factors such as poor air quality 
  • Snow
  • Ice
  • Salt 
  • Original manufacturer construction

The material your car manufacturer chose to make the exhaust pipe with is a huge impactor. Investing a little more in your car’s exhaust system is always better than cutting corners. This is the main contributing factor t the lifespan of your car’s exhaust pipe. 

However, living in the north can also greatly impact the lifespan of your car’s exhaust system. 

Road maintenance is forced to use tons of rock salt in many northern regions. According to the EPA, this salt is similar to table salt in larger granules. All salt is highly corrosive to metal since its electrolytes react to the metallic compounds and break them down.  

When compounded with the cold weather, this is a recipe for decay. Mainly because people are less likely to spray the bottoms of their cars when it’s below freezing outside! 

Your best bet is to get a high-quality exhaust pipe and park it inside to prevent environmental decay. 


Exhaust systems are important for the car’s performance and longevity. It’s also an important environmental factor thanks to the catalytic converter. 

Use non-abrasive soap and hot water to clean your exhaust pipes every few weeks. Avoid bleach, ammonia, and harsh chemicals. 

If your pipes and system components start breaking down, they can’t do their job right! It’s essential to check your system and clean it regularly to prevent decay and corrosion. 


Diesel Net Technology: Exhaust System Materials

National Material: Galvanized Steel: Types, Uses, Benefits.

National Institute of Health: Iron

Metal Tek: What Are Ferrous Alloys?

Great Plains Stainless: The History of Stainless Steel

Energy.Gov: Lightweight Materials for Cars and Trucks

V&F Auto: 5 Ways to Prevent Rust in Your Exhaust System

Metals for You: What is Mild Steel? an in depth technical guide

Help: Summit Racing: Exhaust Material – Mild Steel

EPA.GOV: Winter is Coming! And with it, tons of salt on our roads