Nissan Muffler

FAQs—Nissan Muffler

The big difference between a stainless steel and aluminum muffler is the outer shell. The muffler internals and even the necks of an aluminized muffler are made of stainless steel. However, the outer shell is made of aluminized steel, which comes with a protective coating. A stainless steel muffler uses the same material for its internals and its exterior, which is polished. Although both mufflers may be offered with a lifetime warranty and basically have the same interior materials and construction, a stainless steel muffler is still more durable because its outer shell is constructed using 100% stainless steel. The aluminized muffler has a protective coating, but when this gets scratched off or worn out over time, the rust may get past the protective finish and eat away at the steel.

A vehicle may come with a restrictive exhaust system in order to minimize cost and also to keep it quiet. Restrictions in the system will affect efficiency. With aftermarket or performance mufflers and exhaust systems, what they offer isn’t exactly added power. The performance muffler or aftermarket exhaust is designed to be less restrictive, which improves efficiency as it lets the engine breathe more easily. Because of this, the engine is able to generate more power. This power doesn’t necessarily come from the performance muffler or aftermarket exhaust system. It’s there all along. The performance muffler/exhaust only makes it much easier to squeeze out more power from the engine.

A less restrictive muffler or performance exhaust helps improve engine efficiency. A more efficient engine doesn’t always mean it’s uber-powerful. Efficiency would help the engine squeeze out as much energy as it can get from every drop of fuel. If you don’t get to use all the energy produced for speed or more power, improved efficiency may reflect through better fuel economy and increased gas mileage. The difference in gas mileage may not be that remarkable, but in the long run, the small savings you get will add up, compensating for what you have to spend for a less restrictive exhaust muffler or system.

An aftermarket muffler or exhaust can provide improvements on engine efficiency anywhere between 2 to 10 percent. The improvements in efficiency will reflect through increased horsepower or better fuel economy. The improvements will be more significant or noticeable on smaller cars than on bigger vehicles with larger, more powerful engines. The bigger, more powerful V8 engine, for instance, can get past the restrictions from a stock exhaust. A smaller engine, however, will have a stronger boost in efficiency through a less restrictive exhaust. Improvements in efficiency can go as much as 10% in some cases, although 5% is common.

When the vehicle idles roughly and emits clouds of smoke, this can be a sign that your muffler might be broken or damaged. You can also detect or suspect a problem with the muffler or exhaust if you notice a drop in fuel economy or restricted engine power.

If the muffler is already covered in soot, this usually means that it’s up for replacement. Also check for holes and rust. Water dripping from the pipes also indicates damage and wear.

With a broken muffler, the vehicle may roar louder than before. Thumping or clunking is also a common sign of problems with the exhaust, along with the sharp increase in engine temperature. All these are common signs of muffler damage. Still, it would be best if you’ll have the muffler and exhaust fully checked by a mechanic.

1. I have to replace my muffler and was offered two options in the store: stainless and aluminum. What’s the difference between these muffler materials? If I want a muffler that won’t rust easily, what would be a better choice?
2. Can performance mufflers actually add more power to the vehicle?
3. What if I don’t necessarily drive fast or need more power for speed? What benefits can an aftermarket muffler or performance exhaust offer aside from improved power?
4. In terms of engine efficiency, how much improvement can I expect when I install a less restrictive exhaust or aftermarket muffler? Will these be significant improvements?
5. How can I tell if the muffler is already bad based on changes in vehicle performance? What are the signs?
6. I’m about to go check on the muffler. What are the things I should be looking for to figure out if it’s damaged or still in good shape?
7. Lately, I’ve been hearing some thumping sounds that seem to be coming from the exhaust. The vehicle also roars louder than usual. When I drove the car for a few miles, it almost overheated. Can this have something to do with my Nissan muffler? I just want to confirm before I get it replaced.