Double Trouble: The Pros And Cons Of Replacing A Car's Single Stock Exhaust With A Dual Exhaust System

Replacing your car's stock exhaust system with a dual exhaust is one of the easiest ways to make your car look a little meaner. A well-chosen and well-fitted dual exhaust system can provide significant performance increases over standard single exhaust models, especially when fitted to V-configuration engines.

However, while a properly chosen dual exhaust comes with a number of advantages, the system also comes with a few inherent disadvantages over their simple single exhaust cousins. As such, you should take stock of the needs of both you and your vehicle before deciding on whether a dual exhaust is worth your time and money.

What are the advantages of fitting a dual exhaust system?

Increased exhaust flow: Dual exhaust systems can vent exhaust gases from your car's engine system faster than all but the widest single exhaust systems. This allows fresh air to enter your car's cylinders more quickly, increasing your car's horsepower and preventing waste exhaust gases from lingering too long in your system, a problem which can reduce horsepower and cause soot caking.

Decrease in back pressure: The enhanced airflow provided by a dual exhaust also helps to reduce air resistance which can prevent exhaust gases from quickly and thoroughly leaving your engine system, a phenomenon known as back pressure. This is particularly useful for naturally aspirated cars, as the lack of a turbocharger in this vehicles reduces the pressure and rate at which exhaust gases are expelled.

Increased fuel economy: Because of the increased airflow provided by a suitable dual exhaust system, your car's engine gains access to more oxygen for use in combusting fuel. This increases the amount of energy that your engine can derive from its fuel, increasing fuel economy and reducing the amount of evaporated waste fuel that exits your exhaust.

Aggressive looks: Dual exhaust systems can give even the humblest vehicle an aggressive, high performance look, especially when made from high-end materials such as high-chromium stainless steel.

Enhanced sound: In addition to visual looks, dual exhausts can give your engine a deep, throaty rumble much prized in street vehicles and showpiece cars.

What about the disadvantages of a dual exhaust system?

Limited use with non-V-configuration engines: The primary purpose of a dual exhaust system is to give each row of pistons in a V-configuration engine its own dedicated exhaust system, preventing exhaust backup as both rows of cylinders force their exhaust gases into a single pipe. As such, their usefulness when used with other engine configurations is very limited, although the overall increase in airflow may still convey small increases in performance and fuel economy.

Larger structure: A dual exhaust system is naturally a larger and more complicated system than a single exhaust system, increasing your car's overall weight and giving you more parts and components to worry about if your exhaust should malfunction. They can also cause problems with ground clearance, a particular concern if you intend to take your vehicle off-road.

Increased price: This increased size and complexity also comes with an increased price tag, and you may find that a dual exhaust system is less cost-effective for performance enhancement than other improvements, especially in non-V-configuration engines.