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Flowmaster American Thunder Axle-Back Exhaust (05-09 V6)

100+ Reviews
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  • Item #18404
  • MPN #17421
  • Market Price $267.99
  • You Save 10% ($26.65)
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Customer Photos
  • Aggressive Flowmaster 60-series Delta Flow sound
  • Polished stainless steel 3.5" tip.
  • Durable Aluminized Steel Construction.
  • Includes one Flowmaster muffler
  • Fits 2005-2009 V6 Mustangs.
Flowmaster Sound . The Flowmaster American Thunder Axle-Back exhaust system will improve your 2005-2009 V6 Mustangs exhaust flow for an increase in power and a throatier muscular exhaust note with their patented chambered designed muffler.

Quality Construction. Constructed from durable 2.5" 16 gauge aluminized steel tubing for it's corrosion resistant properties the Flowmaster axle back features a specialty 5" X 10" chambered 60 Series Delta Flow American Thunder muffler with a 3.5" diameter polished stainless steel tip for muscle car looks and sound. As an added bonus the tip is embossed with the "Flowmaster" logo for true custom styling.

Fitment. This Flowmaster American Thunder Axle-Back exhaust system is designed to fit the 2005-2009 4.0L V6 Mustangs for both great looks and great sound.

Americanmuscle recommends adding the 2005+ Mustang 304 Stainless Steel Exhaust Hanger Kit from the drop down option above, to provide more strength, stability and a cleaner installed appearance. If you have a 2007 Mustang you may need the kit for correct installation. Click here for details.

Mustang Fitment: 2005 2006 2007 2008 2009 Details

What's in the Box
  • (1) Muffler assembly
  • (1) Exhaust Hanger
Installation Info
Tech Specs
Axleback Exhaust Specifications
Piping Material: Aluminized Steel Tip Material : Polished Stainless Steel
Piping Size: 2.5" Tip Size: 3.5"
Muffler Type: Chambered Fitment: 05-09 V6 Mustangs
  • V6 - 05, 06, 07, 08, 09

Most Helpful Reviews View All

Overall Rating 4.8/5 Write a Review
Ohhhh Baby...

My word... Got my car, a lovely 09 Mustang, and immediately started looking for a new muffler. Why? Because, the stock muffler STINKS! After a TON of research, I decided on this one. BEST CHOICE EVER!

Read More
Helpful (25) (0)

It Sounds Awesome!

i bought this flowmaster and it arrived in just 3 days. i had it professionally installed and it sounds amazing! it makes your v6 sound soo much better. Next year i plan on getting a true dual with both

Read More
Helpful (25) (2)

Customer Photos (37) View All

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Q & A (6 Questions, 13 Answers) Ask a Question

Around how much horsepower does this add?

etmarx Year: 2007 Model: V6

Question Resolved
Good Question (0) (2)
  • As others have said, it's generally around a 6-10 hp gain. This amount of gain tends to be hard to actually feel but it is there! Hope this helps!

    Helpful (7) (0)

    Best Answer

    LisaS Year: 1992 Model: GT

Show 4 more answers

do i really need the hangar kit for this exhaust for my 06?

Rommel Year: 2006 Model: V6

Question Resolved
Good Question (0) (2)
  • No, it is fine without it because the existing hanger match ip evactly to the stock for a secure fit.

    Helpful (2) (0)

    Best Answer

    mustanglover1 Year: 2006 Model: V6

Show 4 more answers

My alignment is do i fix it? I just installed this axelback with my father & i just love the way it sounds & looks but unfortunately the tip isn't aligned with the cut's more to the left of the cut out. I really want it to be aligned in the center, any advice would be greatly appreciated! Thank you AM!

KevSean Year: 2008 Model: V6

Question Resolved
Good Question (0) (0)
  • This exhaust naturally tends to linger to the left more then the right. but not by much, MAYBE 2cm or less in my case. but if it is a lot more significantly to the left in your case, i would recommend loosening the hangars and maybe even where it connects to your underline exhaust, and have one of you hold it to the right as much as possible to the point where your satisfied with the position, and while holding it in that exact position, have either you or your father tighten every thing back up and see where it goes from there. hope this helps, Goodluck!

    Helpful (4) (0)

    Best Answer

    Rommel Year: 2006 Model: V6

    Top 1000 Contributor

Show 2 more answers

Reviews (100+) Write a Review

  • 5 Stars .88 89%
  • 4 Stars .09 9%
  • 3 Stars .00 0%
  • 2 Stars .02 2%
  • 1 Stars .00 0%

out of 5 stars

100+ Customers Recommend this Product

Installation Time:Afternoon

Installation Cost:0-$100

  • Loudness / Volume: 4.524476 4.5/5
  • Exhaust Note: 4.591549 4.6/5
  • Fit & Finish: 4.748252 4.7/5
  • Bang For Your Buck: 4.706294 4.7/5
Filter By Sort By
  • 5/5

    Ohhhh Baby...

    July 06, 2010

    My word... Got my car, a lovely 09 Mustang, and immediately started looking for a new muffler. Why? Because, the stock muffler STINKS! After a TON of research, I decided on this one. BEST CHOICE EVER! My parents actually bought it and my uncle installed it while I was on a trip. Came home late, cranked up my car, and paused... "Was that..." Looked around back and there was that pretty "flowmaster" chrome tip. It sounds amazing, and trust me, no video does it justice. It has a nice, deep sound. Doesn't "pop" much. Only does it when I start it, and even then only every so often. Muffler is definitely the first V6 mod you should do, and in my opinion, this one is by far the greatest!


    Year: 2009 Model: V6

    Helpful (25) (0)

  • 5/5

    It Sounds Awesome!

    July 04, 2010

    i bought this flowmaster and it arrived in just 3 days. i had it professionally installed and it sounds amazing! it makes your v6 sound soo much better. Next year i plan on getting a true dual with both of these flowmasters on my mustang. i recommend buying this exhaust to get rid of the whiney sound of the stock muffler!


    Helpful (25) (2)

  • 5/5


    March 08, 2010

    Just got it today and installed it right away. it took me two days to pick the right exhaust that would give my v6 what it needed to sound the way it looks. Let me tell you this exhaust sounds great. The flowmaster give the mustang a deep rich sound when u hit the gas. Like another reviewer said i stop listening to the radio just so i can hear it. One bad thing ,well its not that bad but everyone on the road wants to race since i put it on. That is how good it sound. dont take my word go to youtube so you can hear it for yourself. Highly recommended.


    Helpful (13) (0)

  • 5/5


    September 08, 2009

    hey mustang lovers, after looking for weeks for an affordable exhaust system for my v6 stang, i found this. after reading some of the reviews i was skeptical. But i went out on a limb and i am so happy! i had it installed at 9 am this morning and i LOVE it. it sounds amazing when u turn it on and at idle. Acceleration- loud when u want it and soft when u dont. sorry about all the grammar mistakes on my review, im just so excited!!!! buy this product


    Helpful (13) (1)

  • 5/5

    Great Exhaust

    June 16, 2010

    I was a little leary about buying this exhaust. I shouldn't have been. I installed it with every intention of putting the OEM back on if I didn't like it. I won't be taking it off. It gives my 09 Convertible V6 a nice rumble at idle, and you can really hear it during a quick acceleration. Once you reach your cruising speed its nice and quiet. Its not obnoxiously loud at all. I could feel the HP difference immediately. I have nothing bad to say about it and American Muscle delivered it quick. A BBK CAI is next. I hope this helps if your riding the fence.


    Year: 2009 Model: V6

    Helpful (30) (10)

  • 5/5


    September 20, 2011

    sounds amazing, good increase in HP, and looks great!! had it installed at a shop for $40 bucks and it only took them 30 min!!!



    Year: 2007 Model: V6 Driving Style: Daily Driver 'Stangs I have owned: 1 san antonio

    Helpful (10) (1)

  • 5/5

    A wonderful product at a great price

    December 03, 2010

    As a mustang V6 owner (2007) the first thing I wanted to do was get some bolt-ons. I looked at cold air intakes, exhausts, and chips. The first thing I decided to do was this flowmaster exhaust. I am very glad I did. The bolt on horsepower is noticable and the car sounds amazing. at idle the car sounds louder then stock with a deep growl. At about 2500 rpm the note gets really loud and deep sounding identicle to my friends v8 truck with an exhaust. this product will make your stang a lot funner to drive as well as turn some heads. I would buy this again as the first stang upgrade in a heartbeat


    Year: 2007 Model: V6 Driving Style: Daily Driver

    Helpful (8) (0)

  • 5/5


    April 23, 2010

    I do all my mods to my car. This took me about an hour to install with the no power tools. I didn't get the extra $60 hangers and it is tightly in place in an 09 V6. Sound is so buff. I posted a video on YouTube if you doubt its buffness. Throttle response if ridiculously improved. I spent my Tax Refund well. :)


    Year: 2009 Model: V6

    Helpful (8) (0)

  • 5/5

    Easy installation, great fit, and amazing sound!

    September 09, 2011

    Highly satisfied! First mod done to my stang, easily installed in about 45 minutes, amazing sound especially in higher rpm's, and boost in power. I get alot more challenges to race ever since I got the exhaust and I'm happy to say my stock 210 hp v6 pony with Flowmaster exhaust took out an Infiniti G37 S. I highly recommend this product!


    Year: 2005 Model: V6 Driving Style: Street / Strip Los Angeles, CA

    Helpful (7) (0)

  • 5/5

    This product has Excellent qualities!!!

    September 22, 2011

    When i first installed it, just from the looks of it i knew that i qould like it. When you first crank the engine and it starts up man are you SURPRISED at what it actually sounds like. Everyone has heard a lions roar, well thats exactly what you get when you start it up. Idleing like at a stop light you dont hear it at all. But once you hit the gas even just the slightest you can hear and feel the growl throughout the car. All in all this is the best and first thing someone should buy for their Mustang.



    Year: 2009 Model: V6 Driving Style: Daily Driver 'Stangs I have owned: 1 Oklahoma City

    Helpful (8) (1)

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