All Mustang Enthusiasts have asked the same question at some point – what exhaust should I put on my Stang? Well thankfully, that’s a question that we can help you answer. Sure you can turn to YouTube but let’s face it you usually get some cruddy cell phone camera or decent picture with tons of wind noise. As part of our solution we thought we would give you solid test data and consistent comparisons. We also thought, “Why not start with our 2013 Mustang Project High Impact?” So without dragging this on any further lets get down to business.

We tested the following axle back on stock headers and mid pipe.

The test contained a couple parts to provide you with as much detail as possible:

We filmed stationary revs in a controlled environment (our warehouse). This allowed us to cut out all the wind noises and traffic that you often get from filming outside.

We also filmed the outside driving from a camera mount that was mounted in the same spot for all drives. The outside drives were slightly spirited drives shifting at 4,000 RPMs each gear until we hit the speed limit of 70mph.

To give you a better understanding of just "how much louder" the exhaust is we compared them all to a factory exhaust. Since films can be deceiving and don't give you real world answers like "is there a drone" we did the test drives with two people. Nathan, proud 5.0L pushrod guy, and myself, a mod motor guy, took notes after each drive and rated many different aspects of the exhaust.

One last and neat new feature is for both the drive and the inside controlled environment test we used a decibel meter to monitor peak decibel reading on each exhaust. The meter was place in the exact same spot for each test. This allows us to give you a rough percentage of just how much louder or quieter each exhaust actually is compared to stock.

Check out each tab for notes from both Nathan and myself. We did the rating scale on 1-5 with five being the best. To see our final conclusion, check out the summary tab at the end. Enjoy and we truly hope you find these and our future exhaust test useful in your exhaust selection.

Stock 2013 Mustang Exhaust

Don't let the words "Stock Exhaust" fool you when it comes to the S197 cars. Ford really did their homework. These cars definitely have a nice deep growl; especially compared to the old days of the 4 catalytic converter mid pipes and huge/heavy factory mufflers. Despite the less restrictive exhaust on the S197 cars they still get better emission rating. It is nice to see automotive technology advancing.

Ford Racing Sports Axle Back

Jeff's Review:

Scale of 1-5: 5 being the best

City Drivability: 5

Hwy Drivability: 5

Sound “Aggressiveness”: 3

Bang for Your Buck: 2

Looks: 5

Notes: The Ford Racing Sport axle back had one of the best fit and finishes of all the kits we tested. The chrome tips feature a stamped Ford Racing logo (visible in test video). This axle back was just slightly louder than stock on the inside of the car; yet featured a nice deep tone from the outside. It had no noticeable drone or annoying RPM range while cruising. I gave these mufflers the best all-around drivability because of these features. They are the priciest kit we tested but as with the Bassani you can tell you get better quality with the higher price. The only real complaint I have on this axle back is the fact that it wasn’t as aggressive as the GT500 in overall sound. This is probably from the fact that this is a packed muffler and will get a louder over time.

Nathan's Review:

Scale of 1-5:

5 being the best

City Drivability: 4

Hwy Drivability: 5

Sound “Aggressiveness”: 3

Bang for Your Buck: 3

Looks: 5

Notes: I thought this exhaust set up was really similar to the GT500 Axle back with better looking tips. It wasn’t quite as aggressive as the GT500. It being more expensive my choice is the GT500 Axle back.

Ford Racing GT500 Axle Back - Points Winner

Jeff's Review:

Scale of 1-5: 5 being the best

City Drivability: 5

Hwy Drivability: 5

Sound “Aggressiveness”: 4

Bang for Your Buck: 5

Looks: 2

Notes: This had to be the biggest surprise out of the bunch. The GT500 mufflers are nearly same size as factory but save you about 5 pounds per muffler. The finish looks very close to the factory muffler. The biggest complaint from me on the muffler is that it didn’t have a really nice exhaust tip compared to all the others we tested. The tone and sound were great. Because this was not a “canister” style muffler, we didn’t have any drone. The tone was very aggressive and you also can’t beat the price. With me being a “on a budget” kind of guy this would be my first choice for an axle back. The overall drivability was nearly stock but with a much deeper more aggressive tone. This is a very solid choice for a new axle back for your 2011+ Mustang.

Nathan's Review:

Scale of 1-5:

5 being the best

City Drivability: 4

Hwy Drivability: 5

Sound “Aggressiveness”: 4

Bang for Your Buck: 5

Looks: 4

Notes: This was my favorite out of the axle backs tested. It’s aggressive when given gas but quiets down nicely at highway speeds with little to no drone.

Flowmaster Outlaw Axle Back

Jeff's Review:

Scale of 1-5: 5 being the best

City Drivability: 3

Hwy Drivability: 2

Sound “Aggressiveness”: 4

Bang for Your Buck: 4

Looks: 3

Notes: The aggressive tone from this axle back was great on the factory mid pipe and stock headers. The major down side to this axle back was the annoying “drone” you got cruising at about 2k RPMs. To me this is not the exhaust you would want on the car if you did a lot of highway driving. The tips were nice and the overall size of the axle was small which made it easy to install. I was not a fan of the black paint used to coat the rest of the exhaust. It seems like it would chip off or scratch easily. This was the lightest axle back we tested.

Nathan's Review:

City Drivability: 4

Hwy Drivability: 2

Sound “Aggressiveness”: 4

Bang for Your Buck: 3

Looks: 3

Notes: This exhaust is by far the most aggressive sounding exhaust out of the ones tested but it gives up Highway Drivability. This exhaust is loud no matter what speed. It sounds great around town but has a loud drone at 60-70 mph.

Flowmaster Hushpower Axle Back

Jeff's Review:

Scale of 1-5: 5 being the best

City Drivability: 4

Hwy Drivability: 3

Sound “Aggressiveness”: 4

Bang for Your Buck: 3

Looks: 3

Notes: The Hush Power axle back had a deep aggressive tone and managed to eliminate a lot some of the drone of the Flowmaster Outlaw axle back. This axle back still had a drone around 2k RPM but was much more tolerable when compared to the Outlaw axle back. The overall finish was exactly the same as the Outlaw axle back. It had a nice chrome tip but again I just was not a fan of the black paint used to coat the rest of the exhaust. The canister style muffler cut off a lot of weight compared to the factory mufflers and gave more room for installation.

Nathan's Review:

City Drivability: 4

Hwy Drivability: 4

Sound “Aggressiveness”: 3

Bang for Your Buck: 4

Looks: 3

Notes: The Hush Power exhaust gives you a little bit of both worlds. This exhaust is aggressive when in the gas but cruising around town and on the highway it quiets down to a nice level. It does have bit of a drone at 60-70 mph

Bassani Race Axle Back

Jeff's Review:

Scale of 1-5: 5 being the best

City Drivability: 4

Hwy Drivability: 3

Sound “Aggressiveness”: 5

Bang for Your Buck: 2

Looks: 5

Notes: The exhaust tone was one of the best out of all the axle backs we tested. The finish was great. The all metal (no paint/coating) finished looked great from any angle. There was a very slight drone on this axle back around 2k RPM. I noticed it just a little less than the Flowmaster Hush Power. Due to the higher cost compared to the Hush Power it got a lower “Bang for the Buck” rating; however, you can tell that the extra money gets you very high quality fit and finish.

Nathan's Review:

Scale of 1-5:

5 being the best

City Drivability: 4

Hwy Drivability: 5

Sound “Aggressiveness”: 3

Bang for Your Buck: 4

Looks: 4

Notes: I rank this exhaust right with the Flowmaster Hushpower. The exhaust volume was really close to each other. This exhaust doesn’t have as prominent of a drone at highway speeds.

Summary

Below you will find two comparison charts. The first shows Nathan's scores, my scores and an average score for each axle back. The second chart give you a comparison of each exhaust side-by-side. This chart also shows how much louder than factory each test was in percentage form. To make the chart easy to read at a glance, we highlight each test's highest reading in red and lowest reading in yellow.

We ultimately went with the Ford Racing Sport Axle back on Project High Impact. We decided to stick with the Ford Racing theme that the car had taken with the wheels and suspension upgrades. We also felt the GT500 Axle Back in overall looks just did not do Project High Impact the justice it desired. The overall quality and look of the FRPP Axle Back just made a huge improvement to the look of the car.