I was wondering if adding a different muffler like the Flowmaster 40 actually improves fuel economy? I'd like to eventually make my truck "sound" more aggressive, but if switching to a Flowmaster 40 or something similar improves mileage, I would consider doing it sooner rather than later.

Thanks
Sean

 

it improves it slightly, nothing huge though, maybe at max 1 mpg or so. Didnt notice a huge fuel savings to me though.

 

I think that realisticaly, unless your doing the math and driving in a controlled environment, you'll likely not notice much if anything on the fuel savings side. I know most brands like to talk about that, but after years of this I've realized that the reality is I do it for maybe slightly better performance and it sounds better....

 

Adding just the muffler probably wouldn't do much of anything except give you the sound, but add a cat-back system and you could possibly see an extra mile or two. However if you are like 99.99% of the guys on here who love to hear their truck scream down the road then you might actually lose eeven more of your mpg's because you'll be sinking your foot a little deeper into it to hear it or just show off.

 

hehe no doubt!
After driving mini vans for the last 14 years, it's hard not to let that Hemi loose every once in awhile!

What exactly is a cat back system??

Thanks
Sean

 

cat back refers to a new exhaust from the Catalytic converter back to the exhaust tips.

 

Spend a little time at the Flowmaster website.

Notice that everything is written about 'sound'
and very little flow measurements or dyno charts?

Flowmaster has spent millions of $ doing research to give a particular sound to the exhaust.
If you like that sound on a v8...buy the Flowmaster.

Reducing the backpressure in the exhaust can slightly improve MPG
but the effect is greatest at full throttle and goes down rapidly if you are driving at 'part throttle'.

Most driving is done at part throttle, especially on a Ram with a large V8.
Most of the time the exhaust backpressure is already only 1 psi or so at part throttle.

Lowering this backpressure by a tiny 0.2 psi won't improve MPG much in unloaded driving
but will if you tow a heavy trailer or cruise long distances at 90+ mph.

In 2002 Dodge put a new design exhaust system on the Rams that had significantly less backpressure than the 1994-2001 design. Notice in their advertisements that Dodge didn't brag about this new exhaust improving MPG in daily driving? That's because it didn't in part throttle driving like the city/highway EPA tests.

How much did the 2002 exhaust redesign help the full throttle horsepower at different rpms?
About 13 ft-lbs (293 versus 280)

Go to hypertech's website and compare their "stock' dyno graphs on
2001 Magnum 5.9V8s

http://www.hypertech-inc.com/images/...dodge015.9.jpg
against

2002 Magnum 5.9V8s

http://www.hypertech-inc.com/images/...dge02035.9.jpg

What muffler design has the lowest exhaust backpressure?

My opinion is that a 'straight thru' design
like the DynoMax UltraFlo
has no more backpressure than the same length of exhaust pipe,
and the slightly more expensive stainless steel construction will last longer.

This type of design is similar to the resonator that Dodge added to the stock system.

 

i think mine got worse, due to the fact my SUPER 40 sounds so good, all i do is pin it so much!!

 

I agree with 06RAM...... I find myself mashing down the gas to hear that Hemi roar.

 

Eventhough I have the flowmaster exhaust, I still get right around 7-9 MPG... Regardless or stepping on it, or not stepping on it...