New muffler/exhaust - Performance

[Glenn54]

Has anyone replaced the OEM muffler or exhaust and seen an increase in MPG? I imagine there may be a slight increase in horsepower and you may get much better sound.

 

[Rockyroad217]

Has anyone replaced the OEM muffler or exhaust and seen an increase in MPG? I imagine there may be a slight increase in horsepower and you may get much better sound.

You might lose mpg enjoying the new sound of your exhaust

 

[pber1]

You

You might lose mpg enjoying the new sound of your exhaust

I did!

 

[riccnick]

Has anyone replaced the OEM muffler or exhaust and seen an increase in MPG? I imagine there may be a slight increase in horsepower and you may get much better sound.

With anything more "free flowing" from the cat's back, you'll lose more low end torque than you'll ever gain with high end HP. MPG will either not be affected, or go down. But, smiles per gallon goes up!

When you get into headers, midpipes, and a true performance exhaust setup specifically designed for any modern truck, you're A: usually no longer EPA compliant, B: into big $$ territory before you see true net gains across the dyno curves, and C: probably require some tuning to take advantage of any of that free'd up power previously mentioned.

The stock system is deigned to maximize efficiency and minimize noise. And the configuration that comes with our trucks was decided on during a mult-hundred-million dollar development cycle. If there was an extra 15 - 20 horsepower in there without any other side effects, they would have found it.

If you want some cheap thrills and like the noise, a few hundred bucks will git 'r done, and there's nothing wrong that. (I like the noise, I plan on doing something to liven up the experience over stock). Putting any sort of expectation on MPG or power gains without thousands of dollars of investment is going to get disappointing real fast, and honestly isn't guaranteed.

 

[BmoreStew]

You'll lose more low end torque than you'll ever gain with high end HP. MPG will either not be affected, or go down. But, smiles per gallon goes up!

You lose torque with a cat back replacement?

 

[1stTimeRAM]

I did!

Me too...

 

[riccnick]

You lose torque with a cat back replacement?

Most do, at least from what I've seen. There's a whole lot more than meets the eye when it comes to "freeing up" horsepower or torque on a modern engine. Reducing backpressure isn't the one-size-fits-all solution that it used to be, as the bottleneck in the systems aren't the same anymore with the extensive amount of resources available to manufacturers nowadays. Computers can do flow analysis on the entire intake, engine, and exhaust systems in mere seconds, where as 30-40 years ago it took a team of engineers hours and hours and hours. Replacing your muffler and expecting any sort of true gain is ASSUMING the mfg's left a HUGE bottleneck in a system so simple as the exhaust. It's the year 2019. We're 20-25 years MINIMUM beyond finding free horsepower in a new vehicle with anything short of re-engineering an entire system on any vehicle.

 

[Jtc411]

I put on the flowmaster outlaw direct fit muffler and noticed maybe a little more power up top but really it sounds faster. I have not really noticed any real power gain or mpg increase

 

[riccnick]

really it sounds faster

That's the ticket right there. It's just being perceived as faster by your ears. I'd wager a good amount that it averages slower in any performance metric in a controlled environment (even if only minimally).

 

[Glenn54]

Thanks all. Riccnick, you've provided good information. I think I better forget changing exhaust in hopes of getting better MPG. I have a 95 F150 that I had dual exhausts with Flowmaster mufflers. It sounds great but is honestly a little too loud after awhile. I didn't really care about MPG with it because I just drive locally.

 

[J-Cooz]

Most do, at least from what I've seen. There's a whole lot more than meets the eye when it comes to "freeing up" horsepower or torque on a modern engine. Reducing backpressure isn't the one-size-fits-all solution that it used to be, as the bottleneck in the systems aren't the same anymore with the extensive amount of resources available to manufacturers nowadays. Computers can do flow analysis on the entire intake, engine, and exhaust systems in mere seconds, where as 30-40 years ago it took a team of engineers hours and hours and hours. Replacing your muffler and expecting any sort of true gain is ASSUMING the mfg's left a HUGE bottleneck in a system so simple as the exhaust. It's the year 2019. We're 20-25 years MINIMUM beyond finding free horsepower in a new vehicle with anything short of re-engineering an entire system on any vehicle.

Great points. If it was that easy to gain MPG or HP manufactures would do it. I always laugh at the intake and exhaust companies that make ridiculous claims.

I'll be leaving the Ram stock. I'd like a little more exhaust noise sometimes but also love how quiet it is at cruise. Can't have your cake and eat it too so it will stay stock.

 

[riccnick]

Great points. If it was that easy to gain MPG or HP manufactures would do it. I always laugh at the intake and exhaust companies that make ridiculous claims.

I'll be leaving the Ram stock. I'd like a little more exhaust noise sometimes but also love how quiet it is at cruise. Can't have your cake and eat it too so it will stay stock.

People also forget that gaining 10 or 15 HP at 5,500 RPM isn't going to offset losing the same or more torque at 2,200 RPM or 1,500 RPM or whatever the numbers may be. I'd rather see a mfg come out with a product that says hey, we didn't gain any peak power, but we added 50 lbs-ft at 2,200-4,500 RPM. THAT would wake up a vehicle for sure!

 

[J-Cooz]

That's not to say I don't think people shouldn't modify their vehicles. If you like a louder exhaust go for it!

I had a Jeep SRT before this and I put an AFE intake on it. It didn't add any power but it looked great under the hood and the intake temps dropped quicker after sitting in traffic so to me it was worth it.

 

[spaightlabs]

You

You might lose mpg enjoying the new sound of your exhaust

It is a scientific fact that anything that makes a truck sound better when the go pedals pressed will lead to a decrease in fuel economy when operated by any male.

 

[dyelife]

Has anyone replaced the OEM muffler or exhaust and seen an increase in MPG? I imagine there may be a slight increase in horsepower and you may get much better sound.

I just installed the Flowmaster direct fit FX Model 717847.

Flowmaster 717847: Direct-Fit FlowFX Muffler 2019 Ram 1500 Truck 5.7L Offset In/Center Out: 3.000 in. - JEGS

Get the Best Performance with Flowmaster Direct-Fit FlowFX Muffler 2019 Ram 1500 Truck 5.7L Offset In/Center Out: 3.000 in. 717847 parts at JEGS. Shop Now at the Guaranteed Lowest Price!

www.jegs.com

It sounds amazing, there arent too many available for direct fit mufflers on the 2019 yet. For me, it was this or the outlaw. I am super happy with this one. Low growl, great cold start and when you put your foot into it...its nasty. When your cruising, so is it. There is very little drone especially with how quiet the cabin is now in 2019.

I loaded a video of the sound, no revving, I was at work but I can later. I highly recommend it. I tried to upload a video I took but the site isnt allowing it for some reason.

2019 RAM Laramie 1500 4x4 5.7 hemi w/ e-torque

 

[‘19ramlveryeha]

Thanks all. Riccnick, you've provided good information. I think I better forget changing exhaust in hopes of getting better MPG. I have a 95 F150 that I had dual exhausts with Flowmaster mufflers. It sounds great but is honestly a little too loud after awhile. I didn't really care about MPG with it because I just drive locally.

You won’t notice the mpg improvement. It does sound incredible. I left the two resonators out back and it’s perfect. You get a little sound in the cab but while cruising you. Any even hear it.


Sent from my iPhone using Tapatalk

 

[19LaramieRam]

Great points. If it was that easy to gain MPG or HP manufactures would do it. I always laugh at the intake and exhaust companies that make ridiculous claims.

I'll be leaving the Ram stock. I'd like a little more exhaust noise sometimes but also love how quiet it is at cruise. Can't have your cake and eat it too so it will stay stock.

To add a little more insight to this.. the engineering recommendations based on their calculations/results do not always get followed through on in a lot of companies I have seen. It’s more like a half and half, a lot of variables come into play with manufacturing on this scale. Fiat might be big enough to handle making last minute changes and funding reasearch but they are also in the business of making money.
Not saying anyone is right or wrong but you’ll never find more power if you believe you’re looking at a perfect system..

 

[My1stHemi]

With anything more "free flowing" from the cat's back, you'll lose more low end torque than you'll ever gain with high end HP. MPG will either not be affected, or go down. But, smiles per gallon goes up!

I have heard this argument about losing torque before, but may I suggest watching this video of an engine on a dyno being tested with open headers, 2.5” exhaust, and a 3” system.

In their testing Torque is not lost with more flow.

Engine Masters

 

[riccnick]

I have heard this argument about losing torque before, but may I suggest watching this video of an engine on a dyno being tested with open headers, 2.5” exhaust, and a 3” system.

In their testing Torque is not lost with more flow.

Engine Masters

Ok, but 4600 rpm isn't "low end torque", that's a very high peak torque.

And in the video, you can see where the torque was less with open headers compared to the 2" exhaust below 3,000 rpms, which is conveniently cut off on the chart. I know most charts start there but I never really understood why on the the engine dyno's. For rolling dyno's I get it.

 

[Orion10182011]

Your are not likely to lose TQ from a cat back, might not gain anything but sound. Putting too large of primary's on a set of headers yes. It's about exhaust velocity not "back pressure". All back pressure is bad.