SALES & PROMOTIONS
888-99-DIESEL
Email Us
Videos|Blogs

Quick Ship
SKU #: MBRP-M1004 MPN #: M1004

MBRP Armor Series 4" Quiet Tone Diesel Muffler

$359.99
Get 359 points in loyalty rewards
MBRP Armor Series 4" Quiet Tone Diesel Muffler
Description Overview
Running an upgraded exhaust has its benefits for heat dissipation, however it can have its downfalls, also, and mostly in terms of drone and in cab noise. For those that want to reduce the amount of exhaust drone as much as possible in their 4" exhaust, MBRP has the solution! Introducing MBRP's 4" Quiet Tone muffler.  Featuring a high flow 4" spiral louvered core, it will fit most 4" performance exhaust systems. With over TRIPLE the sound canceling packing, this is the muffler you want to tame that diesel drone.

Product photos may not match the selected option. Please confirm your choice before adding to cart.

Enter your zip and we'll see if installation is available.

  • Request quotes from local installers at checkout
  • Compare options and choose the best fit for your install
Free Customer Loyalty Program
No Salesmen, Just Enthusiasts

MBRP's 4" Quiet Tone diesel muffler uses a spiral louvered core with over triple the sound-canceling packing to reduce drone.

Fits
Fits 4" Exhaust
Brand
MBRP Exhaust
Best for
Reducing exhaust drone and in-cab noise on 4" performance exhaust systems
Key features
  • Up to 10% dB reduction compared to regular performance muffler
  • Eliminates drone under load or towing conditions
  • Direct replacement for all MBRP 4" performance mufflers
  • Available in T409 (Armor Plus), T304 stainless steel (Armor Pro), or heavy duty aluminized steel (Armor Lite)
  • True 4" core for maximum flow
Key specs
  • Up to 10% dB reduction

Summarized by AI from this product’s description and specs. Confirm fitment for your year, make and engine before ordering.

Running an upgraded exhaust has its benefits for heat dissipation, however it can have its downfalls, also, and mostly in terms of drone and in cab noise. For those that want to reduce the amount of exhaust drone as much as possible in their 4" exhaust, MBRP has the solution!

Introducing MBRP's 4" Quiet Tone muffler.  Featuring a high flow 4" spiral louvered core, it will fit most 4" performance exhaust systems. With over TRIPLE the sound canceling packing, this is the muffler you want to tame that diesel drone.

Vehicle Fitment
Fits 4" Exhaust
WARNING: Cancer & Reproductive Harm - P65Warnings.ca.gov
FEATURES and BENEFITS:
  • Up to 10% dB reduction compared to regular performance muffler
  • Eliminates drone under load or towing conditions
  • Direct replacement for all MBRP 4" performance mufflers
  • Available in T409(Armor Plus) and T304 stainless steel(Armor Pro) as well as heavy duty aluminized steel(Armor Lite)
  • True 4" core for maximum flow
DIMENSIONS:
  • 4" Inlet
  • 4" Outlet
  • 6" Diameter Body
  • 30" Overall Length
About MBRP Exhaust
Browse MBRP Performance Exhaust Systems Online by Make, Model, and Year. For over twenty years MBRP Exhaust has been delivering performance enthusiasts the most in power, the most in product quality, and the most in customer responsiveness you could possibly expect from exhaust. It all began with the now famous B&B Eliminator, which soon achieved the status as the best selling performance snowmobile silencer of all time. Starting from little more than a vision and an absolute passion for all things performance MBRP inc. is now at the forefront of performance exhaust technology. Marshalling over ten decades of manufacturing and marketing expertise between them, the MBRP design team developed a line of performance diesel exhaust products that has made the rest of the industry take notice, and rush to catch up.

Offering all of its diesel systems in aluminized, T-409 stainless, T-304 stainless, aluminized black, and with and without a muffler ensures that there is an MBRP exhaust for every customer's need and pocketbook. Full bolt-on design and clear, well written instructions mean that consumers can install most of MBRP's systems with minimal tools and in under forty-five minutes. And for everyone, toll free technical support that can talk even the least experienced installer through the process.

MBRP offers many kits in both single and dual outlet configurations. While the performance gains are the same for duals and single systems, the duals offer a deeper more aggressive sound over the single system. This is due to the extra tail pipe and the fact that most dual systems have a slightly different muffler configuration than the single systems.

MBRP even manufactures their "Smokers" kits, which are single and dual in-bed STACK kits to deliver to the hardcore enthusiasts! These kits are available in an assortment of sizes and styles, such as 5" and 6", with turnouts and mitre (angle) cuts. Smokers kits are even available in the new popular BLACK finish for that truly sinister look!!!

The muffler used on all of MBRP's diesel systems is a straight flow through design with a spiral louver core. The muffler is packed with stainless steel wool which is then wrapped with a ceramic fibre blanket to ensure longevity of the muffler. This combination creates the deep mellow exhaust note that MBRP systems are known for.

While performance gains vary depending on the vehicle, you can expect a gain of 5% to 10% in horsepower and torque. For example, with a 2005 GM Duramax diesel, you will see a gain of 18 HP. and 28 ft/lbs measured at the rear wheels. You can also expect a reduction in exhaust gas temperature (EGT) by approximately 200 Degrees F.
Video
Diesel Talk | MBRP Exhaust Kits
When your diesel truck sounds good, you feel good. MBRP has you covered with 4” or 5” sizes and a choice of straight pipe or a muffler. Choose from three different materials; ARMOR LITE (Aluminized), ARMOR PLUS (409SS), or ARMOR PRO (304SS), and don’t forget to finish it off with a tip! Get ready to fall in love with your truck again without breaking the budget.
Video
Diesel Talk | MBRP Exhaust Systems
Looking for more power, better sound, and improved efficiency? MBRP exhaust systems deliver it all! Designed for maximum airflow and durability, these exhausts reduce backpressure, enhance performance, and give your ride that deep, aggressive tone. Whether youre towing, racing, or daily driving, MBRP has the perfect system for you.
Blog
See all
Jeep Gladiator Diesel Problems: Common Issues Explained
April 20, 2026
Jeep Gladiator Diesel Problems: Common Issues Explained
Built by Josh Ullrich
This article covers some of the most common Jeep Gladiator diesel problems, what to watch for, and...
  • dieselengines
  • dieselfueleconomy
  • diesel_exhaust
  • gladiator
Read MoreJeep Gladiator Diesel Problems: Common Issues Explained
How to Make My Truck Louder: Exhaust Sound Tips & Upgrades
December 22, 2025
How to Make My Truck Louder: Exhaust Sound Tips & Upgrades
Built by Josh Ullrich
Learn how to make your truck louder with exhaust tips, mufflers, and safe upgrades. A clear guide...
  • dieselemissions
  • dieselengines
  • diesel_exhaust
Read MoreHow to Make My Truck Louder: Exhaust Sound Tips & Upgrades
diamondeye-banner2
May 08, 2024
The Right Pitch For Any Build: The Top Diesel Exhaust Systems
Built by Artie Maupin
Journey through the world of diesel truck exhaust systems in this comprehensive story. From cat-back exhaust systems...
  • diesel_exhaust
Read MoreThe Right Pitch For Any Build: The Top Diesel Exhaust Systems
What Causes White Smoke From a Diesel Engine?
October 05, 2026
What Causes White Smoke From a Diesel Engine?
Built by Josh Ullrich
White smoke from a diesel engine means different things depending on when it shows up, how long...
  • fuelinjector
  • whitesmokecauses
Read MoreWhat Causes White Smoke From a Diesel Engine?

Overall rating: 4.4347825 / 5 from 46 reviews.

AI Generated Review Summary

MBRP's 4" Quiet Tone Diesel Muffler offers a high flow spiral louvered core designed to significantly reduce exhaust drone while fitting most 4" performance exhaust systems. Customers appreciate its quietness and sound quality, making it ideal for those seeking a quieter ride.

Summary topics

  • Quietness in Truck (23%): Opinions vary, but this truck is quiet enough to carry on a conversation without hollering!
  • Sound Quality (26%): A significant amount of customers expressed appreciation for the great sound and quietness of the product.
  • Muffler Performance (36%): Many customers pointed out that the muffler is great and perfect for 5.9L Cummins.

Review topics: ["shipping","muffler","sounds","truck","noise","impact","cummins","drone","rumble"].

Review highlights

  • "perfect muffler great sound" — Ronald S.
  • "Awesome tone, eliminates drone when your in just the right gear at just the right engine load." — F. E.
  • "Installation was easy, as the ends of the unit slip right over 4" exhaust pipe." — Neal H.

Reviews

Great Muffler!

"This muffler was just what I needed to quiet down my 2018 Ram w/heavily tuned 6.7 Cummins turbo Diesel engine. I highly recommend this muffler and this company. Although it didn’t quiet down my Cummins as much as I had hoped, it did make it way more pleasant inside my truck. Great service and fast shipping."

— Michael P. (5/5)

Not quite

"I was disappointed Wanted quite not quieter"

— Thomas J. (1/5)

Need one of those.

"Works great. Takes the snap and obnoxious droning out. Not hard to install using stainless bands."

— Van W. (5/5)

The description of product

"The description of the product doesn’t match. Comes out much ugly than the picture! But it does what it supposed to do!"

— Leonel P. (3/5)

5 stars

"The construction and look of the muffler is quality. But I am still working to finish the install. Being I had to purchase exhaust system in pieces."

— Paul S. (5/5)

Perfect muffler for my 5. 9L Cummins with stacks

"The MBRP Armor Series 4 reduced the exhaust noise on my 2007 Ram 2500 5. 9L by about 80%. The best thing is there was no negative impact on power, mileage or exhaust temps. And it only took me 55 minutes to make two sawzall cuts to the pipe and clamp the muffler into the same place. When I previously installed twin stacks on my Ram, the interior and exterior exhaust decibels were staggering and uncomfortable for passengers. Now it is comfortable to ride at any speed, even with the windows open."

— Brian P. (5/5)

Perfect muffler for 5. 9L Cummins with stacks

"When I put stacks on my Ram 2500 5. 9L the interior and exterior decibels were staggering. Nice, but uncomfortable for passengers. The MBRP Armor Series 4 reduced the decibels by about 80%, no impact on power, mileage or exhaust temps. And it only took me 55 minutes to make two sawzall cuts to the pipe and clamp the muffler in the same place."

— Brian P. (5/5)

mbrp 4inch quiet muffler

"this item does not knockdown 3 times the noise i would love to send it back but it takes a act of congress to get in touch with these people !!"

— Stephan a. (1/5)

Well done!

"Well done!"

— Scott S. (5/5)

Good muffler

"Ordering was easy, shipping was prompt, install was quick and easy. While my truck is not as quiet as stock, it is quiet enough to be able to carry on a conversation without hollering!"

— Tom M. (5/5)

Q&A

I have your 4” exhaust on my truck, I do t have much drone noise in the cab. I’m thinking about putting this muffler on my truck for the sole purpose of quoting down the external noise of the truck, winter time cold starts at 4:00 am is pretty loud. How much will is quite down the exterior sound of the exhaust?
This would actually be a great way to cut down drone due to the overall design and the fact its a 30" muffler, so pretty good length compared to alternatives. Especially if your truck is currently straight piped, this will make a very noticeable difference as this will even drop decibels by 10% compared to other comparable mufflers, while not hurting performance.
I have a 4” exhaust on my Cummins. Recently took off the short (18”) muffler and installed a 51” muffler. My truck is fairly loud due to the new Hamilton cam kit. But now it’s too quiet! I’m thinking of giving this 30” muffler a shot. Has anyone else gone from a 51” to a 30”???
You bet, sounds like you had either the Big Dog or Donaldson muffler, which does a great job of quieting the truck down, but for some, maybe a little too much. This 30" M1004 gives the truck a nice sound while cutting way down on drone compared to a straight pipe.
I just replaced a 5” exhaust and it had a 30” no name muffler. Because had a lot of drone when pulling and loud .so I ordered a 4” exhaust that come with a 30” no name muffler as well . because I was told it would be quieter then the 5”. But it seems like it almost as loud a the old one .. do u think it might be the no name muffler and using the MBRP 30” would help inside the cab and out .
That would really depend on the style of muffler that came with your current exhaust kit. That being said this MBRP quiet tone muffler does cut down on drone quite a bit.
Mbrp says that muffler should be installed so that exhaust flows over the louvers,and not under so as to obstruct flow. My muffler must have been made wrong,because both ends of muffler have louvers the wrong way,sticking up. Also it is not a spiral core. Is it a piece of junk or what??
That is correct for a diesel truck. MBRP says "Both ends are louvered, the one end pulls the sound waves into the outside chambers and the outlet louvers let the exhaust flow out. This is a high flow chamber design and was made to tone down the sound after 1500 rpm on a diesel engine and keeps the sound close to the 1500 rpm though the rest of the rpm range." -Mark
Does it come with 2 exhaust clamps?
This does not, MBRP intends on you using pre-existing clamps. We do offer exhaust clamps by themselves. -Mark
Cart  ()

You have no items in your shopping cart.

You may also like

Order Summary

Spend $199.00 more for free shipping!

Order Notes

Have a discount code? Enter it at checkout for savings!
View cart