Last Updated: 10.12.2020

Construction-wise, six-cylinder engines are possibly the most balanced. That means you’d get fewer vibrations and less clatter from it. Hence it’s no surprise that a lot of diesel engines on new trucks don’t sound exactly like how one on a tractor would. But that’s not the only thing that’s stopping the engine from creating a ruckus every time you take your vehicle for a drive. And that’s the muffler we’re talking about. It’s an integral part of a vehicle’s exhaust system and is responsible for making the vehicle silent. Let’s take a look at how it achieves that, and if there’s a need to do that.

6-cylinder Diesel Engines

Before going any further, let’s think of a popular vehicle with a 6-cylinder diesel engine on it. It’s hard to miss the Ram range of trucks because the Cummins 6.7 engine fits the description perfectly. It’s a well-developed, reliable engine that has tirelessly over the years ensured the Dodge/Ram customers happy ownership experience. Its six-cylinder construction might not be as sonorous as a V8, but it’s efficient, powerful, and makes decent noise as well. In terms of power and torque, if you’re looking at the range-topping models, you can expect about 400 hp of maximum power and up to a whopping 1000 lb-ft of maximum torque. That comes in handy when you take on big challenges like altering the rotational speed of Earth, for instance.

Why Do You Need a Muffler Anyway?

Okay, back to the serious bit. Why do you need a muffler? That’s a simple question and it has a very simple answer. Without a muffler, your car/truck/automobile will sound like it’s shouting at the top of its lungs without making any sense. You see how in vehicles when you accelerate, the noise increases. That’s one way of knowing that the engine is working its way to build speed up, right? If you remove the muffler, it’ll be so loud even at idle engine speeds, that you wouldn’t even dare push that gas pedal. So the basic reason why mufflers exist is to regulate the sound that comes out from the exhaust. An ideal muffler would silence the engine entirely, like a good pair of noise-canceling earphones.

With its sole purpose out of the way, let’s also take a look at what makes the muffler this magical device that turns ear-throbbing noise into something more pleasing. The muffler is the final chamber on the exhaust before the tailpipe. It consists of pipes inside that have holes in them. To keep this simple, the muffler has such an arrangement within it that when sound waves travel in it, another set of sound waves are emitted simultaneously that cancel those out. That ideally means there’s no noise at all. And while it’s not possible to make the muffler and its resonator in such a way that all waves are canceled, the arrangement does ensure that the overall noise is brought down drastically.

But What if you Need Your 6-Cylinder Diesel Engine Vehicle to Sound Better?

A good quality exhaust system will handle that for you. For instance, if you’re looking for an aftermarket exhaust for the 6.7 Cummins, we have a whole guide on these to check out at your leisure.

Most aftermarket exhaust systems are cat-back units. With such an arrangement, installing and uninstalling the system is made fairly easy. But not only that, aftermarket systems are made in such a way that your vehicle is bound to sound better. You can choose between exhausts that offer a slight advantage over the stock unit, ones with aggressive sound outside but moderate noise inside, and the loud ones that not only announce your arrival from half a mile away but will also ensure that you enjoy the increased noise inside the cabin as well.

All new exhausts are made using precision techniques, to ensure they fit well. And unless specified, most bolt-on ones use factory hangers as well. The difference between exhausts then lies in the material. The most popular ones are aluminized steel and various varieties of stainless steel. The cat-back exhausts don’t affect the emissions, but the ultra-loud ones might miss out on mufflers. That makes them loud, but of course, with better sound than the stock exhaust, even if you were to take the muffler out from the latter.

In a Nutshell

So there you have it — a clear explanation of why 6-cylinder diesel engines come with a muffler. If you want to upgrade your vehicle’s sound characteristics, do keep a few things in mind. Firstly, ensure that the system is cat-back, that will take care of the legalities. Secondly, if you’re picking up a bolt-on kit, do confirm with the Amazon seller/brick-and-mortar store whether the exhaust will fit your truck perfectly. Thirdly, while it’s easy to get carried away when shopping for an aftermarket unit, do note that the ultra-loud ones also produce a lot of in-cabin droning. This can get extremely irritating. Also, the noise levels need to be kept a check on, especially if you’re planning to do everyday driving or even track days in the truck.

The muffler is there for a reason, and as long as you aren’t changing the exhaust system, it’s best to keep it on. Without it, the truck will sound like trash, and you’re most likely going to have irritated neighbors.