Exhaust material, GTI owners, your opinions?

[kaanage]

I'd love to see the price of a titanium exhaust!!!

For the non-technically minded, aluminized steel is like galvanising except for using aluminum rather than zinc as the coating (or alcad aluminum with mild steel being covered by raw aluminum instead of the body metal being an alloyed aluminum) - it's nothing like an alloy.

The fatigue properties of stainless may be better up near the turbo outlet where the operating temperature is high (this is where titanium really shines) but welds can be brittle and crack from vibration (although the welds will be as corrosion resistant as the rest of the sheet while this will not be the case with an aluminized steel fabrication). The other advantage of stainless steel is that scratches won't affect the corrosion resistance while aluminized steel will rust if the the scratch is deep enough to go through the aluminum cladding (something for the slammed crowd to consider).

Tensile strength of mild/aluminized vs stainless steel isn't very different (assuming both have been cold worked to a similar degree) but mild/aluminized steel is much easier to work with.

stupid americans, can't even correctly spell an element

What's wrong? We use the terms "sway bars" and "shock absorbers" so why not aluminum (and gasoline and tires)