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Product Comparison

Glasspack mufflers and steelpack mufflers are two common types of aftermarket exhaust components that can impact the sound and performance of a vehicle's exhaust system.  Let's compare the attributes of both types.


Construction and Durability

The construction of a glasspack muffler consists of a simple design of a perforated inner tube wrapped in a layer of sound-absorbing material; usually fiberglass packing enclosed in a metal casing.  The glasspack muffler is oftentimes considered less durable than a steel-packed option as the fiberglass packing deteriorates over time due to the effects of heat and moisture.  This can lead to a change in sound and reduced effectiveness.  As the fiberglass wears down, the sound quality gets worse and if you were to look on the inside – all you might find is an empty can.  

 inside of our mufflers

In the tradition of quality, each steel-packed Porter Muffler is handmade using only the best heavy-gauge and high-quality steel products sourced in the USA.  Our mufflers feature a unique interior chamber that is fitted with a gapped steel spiral core and packed with stainless steel wool which will not break down and deteriorate.  Stainless steel wool is highly resistant to turbulent exhaust flows and temperatures to prevent blowout offering thermal resistance up to 850C or 1550F.  One source cited that mufflers packed with stainless steel wool will last up to 4 to 5 times longer than by using fiberglass alone.  We believe our Porter Mufflers are the most durable in the market.  In fact, we guarantee it – please refer to our Million Mile Guarantee. Porter Mufflers Million Mile Guarantee


Sound and Air Flow

Glasspacks are known for producing a distinctive and aggressive sound, however, interior ‘drone’ is a serious problem with exhaust modifications.  That’s especially true of anything that promises to be loud and deliver more horsepower at a low price.  Many glasspacks struggle with drone which can be obnoxious at highway speeds.


Our Porter Mufflers produce a mellower and deeper exhaust note compared to traditional glasspacks.  The stainless steel packing helps with dampening and controlling the sound and provide slightly better performance gains compared to glasspacks due to the packing material’s inherent properties.   Our stainless steel-packed mufflers offer a good balance between performance and sound control, along with enhanced durability and corrosion resistance.  We invite you to get Porter-equipped and experience the difference!