Stainless Steel Exhaust Care
T-304 Stainless Steel is a premium alloy containing a minimum of 18% chromium and a minimum of 8% nickel along with other alloying elements. It is the preferred alloy for the manufactur of products subject to high heat and corrosive conditions. Chromium increases the hardenability of the steel and makes it more resistant to corrosion and oxidation. Nickel strengthens the steel and further increases its resistance to corrosion and oxidation.

Will It Stain?
Yes. The name says it all. It’s stain-less steel, not stain-free steel! Nevertheless, it will stain much less than other steels or alloys and it will never rust (which is probably the reason it was purchased). With proper care, staining can be minimized or eliminated. Frequent washing (only clean your exhaust after it is cool to the touch) with hot water and a mild low acid detergent will help to maintain the polished look of your new exhaust as long as possible. If it is necessary to remove oil or road tar, wait for the system to cool, wash first with mineral spirits and immediately wash with soapy water, rinse off with hot clean water, then buff dry.



Organic compounds picked up from the road including engine oil and antifreeze, if left on the exhaust, will eventually bake onto the metal and will be extremely difficult to remove. If left on long enough, the color of the organics will change to a black or a dark reddish brown that may resemble rust. At this point, the only way to clean the surface is to scrub with a fine stainless steel wool pad, wash with hot soapy water, rinse with clean water and buff dry.

Why does Stainless change color?
When stainless steel is heated up, several of the alloying elements will precipitate out and migrate to the surface thereby affecting the color. The first element to precipitate out is carbon, which gives the metal a gold sheen. No amount of polishing will remove it. This is the result of large quantities of unburned hydrocarbons from the engine continuing their combustion further down the exhaust (an engine running too rich or too lean), and the excessive exhaust heat is carried down the exhaust. When the exhaust turns blue-ish, it is the result of excessive heat changing the structure of the chromium crystals in the metal (the result of an engine constantly running too lean a fuel/air mixture). In either case, one should have the engine looked at by a professional mechanic.