Author Topic: Straight through exhaust  (Read 7610 times)

Richard Nicholls

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Straight through exhaust
« on: January 30, 2009, 02:54:48 AM »
We have a 2004 Marquis with a C-12 and I'm trying to increase fuel efficiency.  I have installed an AFE oil washed air filter which seems to have increased mileage +/- 1/2 mpg.  My next step is a straight through exhaust.  I'm looking at either an aero performance or Magna flow.  Has anyone done this?  Has anyone feedback?

Thanks....   Richard Nicholls


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Re: Straight through exhaust
« Reply #1 on: January 30, 2009, 03:29:47 AM »
Several years ago I put an Aero muffler on my '90 Marquis and after the muffler and a valve adjustment there was a notable increase in our MPG.  I can't tell you which have more of an  influence on the mileage but it made me feel better and with a little better power.  I know there are several Marquis owners who also put Aero mufflers on their coaches but have not heard of any extra efficiency.  They are certainly louder than a regular muffler.  I can't speak for the other muffler.
Mandy Canales :)


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Re: Straight through exhaust
« Reply #2 on: January 31, 2009, 02:58:14 AM »
About 2 years ago, I installed the oil air cleaner and Aero exhaust to my 2001 Maraquis, C-12.  The mileage improved about 1 MPG and I think the performance improved also.  Coaches that use to pull away on hills, do not leave me behind anymore.  The noise is not noticable inside the coach until you drive beside a concrete wall or use the Jake brake,  I would recommend both additions.