Does exhaust decrease gas mileage?

Little1er · 05-26-2010, 04:48 PM

A simple question. Does adding aftermarket exhaust decrease your fuel economy? If so, by how much and what exhaust are you using?

Dackelone · 05-26-2010, 05:16 PM

Depends on how heavy your right foot is!

I think as with any mod... you will want to hear your loud-er exhaust... so yes, your gas mileage will decrease. Thats normal. But technically, I do not think a sport exhaust will have any real effect on your gas mileage.

BerkTechnology · 05-26-2010, 05:38 PM

If your right foot stays out of it, a well designed performance exhaust should INCREASE your gas mileage.

ridin135 · 05-26-2010, 05:43 PM

Quote:

Originally Posted by BerkTechnology

If your right foot stays out of it, a well designed performance exhaust should INCREASE your gas mileage.

+1 less restriction=less work=less energy also its lighter. But you wont be seeing noticable gains.

ennislaw · 05-26-2010, 05:43 PM

In theory, a well-designed exhaust system should improve your gas mileage due to a better exhaust flow; in practice, as Dackelone points out, that doesn't usually happen, lol.

pge

igom3 · 05-26-2010, 06:32 PM

My milage was increased after installing Full Berk Sport Exaust with Macht Schnell downpipes.

M II · 06-01-2010, 05:26 PM

Quote:

Originally Posted by Little1er

A simple question. Does adding aftermarket exhaust decrease your fuel economy? If so, by how much and what exhaust are you using?

A louder, more aggressive exhaust tone always brings the heavy foot for me regardless. In theory, you should be leaning out your AFRs a bit so technically you should seen an improvement in MPG as long as the throttle inputs are identical and load is identical.

ianc · 06-01-2010, 10:49 PM

Quote:

In theory, you should be leaning out your AFRs a bit so technically you should seen an improvement in MPG as long as the throttle inputs are identical and load is identical.

Think again; less back pressure = more airflow = more fuel needed to maintain stoich = increased consumption...

ianc

AZ135 · 06-02-2010, 02:07 AM

Quote:

Think again; less back pressure = more airflow = more fuel needed to maintain stoich = increased consumption...

In a NA car yes, but in a turbo car the turbos provide ample back pressure for the engine.

moff · 06-02-2010, 02:17 AM

My fuel consumption has gone up, mainly because I can't resist hearing the amazing noise

M II · 06-02-2010, 09:52 AM

Quote:

Originally Posted by moff

My fuel consumption has gone up, mainly because I can't resist hearing the amazing noise

Yep....this would definitely be the main factor.

05-26-2010, 04:48 PM	#1
Little1er Private First Class 35 Rep 196 Posts Drives: '08 BMW 135i Join Date: Apr 2010 Location: Moraga, CA iTrader: (1)	Does exhaust decrease gas mileage? A simple question. Does adding aftermarket exhaust decrease your fuel economy? If so, by how much and what exhaust are you using?
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05-26-2010, 05:16 PM	#2
Dackelone European Editor 10539 Rep 22,992 Posts Drives: N54 e82 Join Date: Feb 2010 Location: Bayern, Germany iTrader: (1)	Depends on how heavy your right foot is! I think as with any mod... you will want to hear your loud-er exhaust... so yes, your gas mileage will decrease. Thats normal. But technically, I do not think a sport exhaust will have any real effect on your gas mileage.
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05-26-2010, 05:38 PM	#3
BerkTechnology Lieutenant Colonel 223 Rep 1,565 Posts Drives: Fast Join Date: May 2008 Location: Irvine, CA iTrader: (1)	If your right foot stays out of it, a well designed performance exhaust should INCREASE your gas mileage.
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05-26-2010, 05:43 PM	#5
ennislaw NCO 13 Rep 641 Posts Drives: 2010 BSM 135i M-Sport Join Date: Nov 2008 Location: RTP iTrader: (0)	In theory, a well-designed exhaust system should improve your gas mileage due to a better exhaust flow; in practice, as Dackelone points out, that doesn't usually happen, lol. pge Last edited by ennislaw; 05-26-2010 at 06:39 PM.. Reason: Grammar
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05-26-2010, 06:32 PM	#6
igom3 Major 76 Rep 1,147 Posts Drives: 02 E46M3 15 F80 M3 16 X5 35d Join Date: Mar 2009 Location: San Diego iTrader: (1) Garage List 2016 X5 35d [0.00] 2015 BMW M3 [0.00] 2002 E46 M3 [0.00]	My milage was increased after installing Full Berk Sport Exaust with Macht Schnell downpipes.
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06-02-2010, 02:17 AM	#10
moff Colonel 1363 Rep 2,495 Posts Drives: X4M Competition Join Date: Jan 2008 Location: Nottingham GB iTrader: (0)	My fuel consumption has gone up, mainly because I can't resist hearing the amazing noise __________________ Arrived! 2022 X4M Competition, SPY + Black Merino Gone: 2019 X3M Competition, Toronto Red, Adelaide Grey.
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