Hey guys, I have an 03 ram quad cab 4wd with the hemi.. I am looking for the best exhaust to increase my MPG's.. anyone have any advice, or how much it has helped?? thanks

 

Not any of them really help at all. I my self like magnaflow.

 

A simple exhaust wont show much gains at all.You will need to upgrade its intake flow to gain anything on the other end.But in response to your question,I ,personally, am a fan of Flowmaster.

 

I dunno man,I am pretty skeptical about those testimonials.But I guess if you can keep your foot out of it then MAYBE i will believe it.lol its just soooo hard to not step on it to hear the roar

 

The backpressure in the stock exhaust
at part throttle is already low
because the engine is at low rpm and being restricted by the throttle
so the MPG gain is modest...real but modest.

The best exhaust for MPG
would be as low a backpressure at part throttle cruise as possible
...you could drop from about 1 psi to maybe 0.5 psi

Custom headers with primary pipe lengths about 40 to 50 inch long
would help a bit more
by tuning the 'resonance' of the low pressure exhaust low pressure wave
to arrive back at the exhaust valve in the 1700 to 2000 rpm range
where less exhaust gas left in the cylinder
will have a slight effect on burn rate
and make the engine behave as if the timing had be slightly advanced.

All the Dodge truck engines have retarded timing so they can run on
87 to 89 octane gasoline most of the time without pinging
so that there are slight MPG advantages to quicker burn
as long as the weather is not too hot and dry
where you can go too far toward pinging or serious detonation.

The 5.7 with its twin sparkplugs is least retarded in ignition timing
...within 5 degrees of 'mean best torque'
according to a Chrysler employee who worked in their dyno evaluation dept.

 

There is also a slight MPG advantage
to relocating the exhaust pipe tip
to face directly rearward
rather than at 45 degrees to the side.

The side exit is there for safety
...it keeps deadly carbon monoxide gas
from having the chance to build up inside a towed trailer.

You will notice most cars have a direct rearward exhaust outlet
but nearly all cars don't.

The Porsche Boxter exhaust
in the center rear exhausting slightly upward
is probably the best setup from a fuel economy/ultimate top speed
design, as in this position the low pressure area behind the rear bumper
can be partially neutralized.

 

You are not going to get a straight and accurateanswer. Just get the one you like in terms of sound.