It might not add extra power, but a new exhaust system will improve your car’s performance. 

By improving the efficiency of the car’s exhaust system, you can increase your car’s power. Most mass produced cars roll off the assembly line with "restrictive" manufacturer’s exhaust mufflers. These are designed to reduce the car’s noise. However, they also curtail the car’s performance, by forcing the exhaust gases to exit through a smaller bore, or hole, than is ideal.

After-market performance exhaust systems enlarge the aperture which improves the engine’s efficiency and reduces fuel consumption which unlocks extra power. Also, pay for a good quality exhaust system, because the cheaper mufflers are often exhausts filled with fibreglass materials to muffle the noise. This fibreglass can easily overheat and melt on long trips, and end up blocking your exhaust system and consequently reducing your car’s performance.

Dual exhaust systems can look good but are usually a bad idea, especially on small displacement four-cylinder engines. Your car requires one exhaust system per exhaust manifold, and most small cars have only one, so splitting the system in two does not help.

Depending on the type of car you have, and the exhaust system or muffler you choose, you can expect to increase your car’s performance by about 3 per cent. You can use that 3 per cent as the equivalent amount of extra speed, or reduced fuel consumption if you continue to drive at the same speed.

Although 3 per cent may not sound like much, it adds up over time and is a significant cost saving for a car driven every day. Smaller cars tend to benefit the most from the addition of a performance exhaust system. A typical four-cylinder engine must work much harder than a larger car or truck to push the exhaust through the standard restrictive exhaust.

By adding a less-restrictive muffler you can boost the engine’s performance by 5 per cent to a maximum of about 10 per cent, depending on the fuel injection system and other factors.

Exhaust system retailers and installers advise that it is essential that you choose an exhaust system that fits your vehicle’s power band. Big is not better – choose a system with an exhaust pipe that has a similar diameter than the factory-installed pipe.

Diesel engines can benefit from larger exhaust pipes, but most cars leave the factory with pipes at the optimum width. It is the muffler that tends to let you down when it comes to performance.

To keep car’s sale price down, cheaper mufflers are usually installed. They are also designed to reduce noise levels rather than enhance the engine performance.

Enlarged exhaust tips can add to a car’s visual appeal, but they make no difference to performance, so go as large as you like. What matters most is the size of the pipe between the catalytic converter and the exhaust tip.

Basically, by replacing the standard exhaust with an after-market performance muffler or exhaust system, you will boost your car’s engine efficiency from 2 per cent to 10 per cent. This extra efficiency can be used to either increase your car’s horsepower or improve its fuel economy.