Can a 4" exhaust actually increase MPG ??? - Dodge Cummins Diesel Forum
94-98 Non-Powertrain Discussion of 94-98 Topics Not related to the Powertrain...NO ADVERTISING

Closed Thread
 
LinkBack Thread Tools Display Modes
post #1 of 41 (permalink) Old 02-01-2013, 12:18 AM Thread Starter
Cummins Nut
 
memphis04's Avatar
 
Join Date: Nov 2007
Location: Fort Worth Texas
Posts: 328
Thanks: 2
Thanked 8 Times in 8 Posts
iTrader Score: 0 reviews
Can a 4" exhaust actually increase MPG ???

Ive searched all kinds of threads and websites and all I can find are people saying yes or no. Does any body have any hard evidence that it helped or was there just no gain? Is it a waste of money to put in on the truck?


1992 Single Cab LB 4x4 5spd pump turned up a bit, custom intake, 4' DE Exhaust, DennyT Fuel Pin, 3.54 gears, leveled in front, JI Flatbed
(NEW) 1998 Ex. Cab LB 2500 4x4 5spd stock 12V w/132K Grail Truck
memphis04 is offline  
Sponsored Links
Advertisement
 
Sponsored Links
Advertisement
 
post #2 of 41 (permalink) Old 02-01-2013, 02:02 AM
Diesel Head
 
admorrow's Avatar
 
Join Date: Jul 2010
Location: CenCal
Posts: 1,097
Thanks: 3
Thanked 55 Times in 48 Posts
iTrader Score: 1 reviews
Are you saying going from a 5" or stock exhaust?

97 4x4 built auto,Fire rings,a1000,5x.014s, 215 from seth, 62/68 sxe s480.
admorrow is offline  
post #3 of 41 (permalink) Old 02-01-2013, 09:07 AM
Diesel Head
 
GAmes's Avatar
 
Join Date: Sep 2009
Location: Killeen, TX
Posts: 11,063
Thanks: 111
Thanked 1,304 Times in 1,126 Posts
iTrader Score: 7 reviews
I have 800,000 miles of logs that show absolutely no gain in mileage when I installed a 4" MBRP exhaust. I only replaced the stock exhaust because the original rotted out. A person I know who tested products for TST did extensive work on the dyno and found that a 4 inch exhaust did not make any difference in power or egts until the engine was making over 400HP at the wheels.

97 3500, 2 WD, G56, slightly bombed, 1.2 million miles. Started the second million on 8/24/13
If you are lucky enough to be in Texas, you are lucky enough.
GAmes is offline  
post #4 of 41 (permalink) Old 02-01-2013, 07:10 PM Thread Starter
Cummins Nut
 
memphis04's Avatar
 
Join Date: Nov 2007
Location: Fort Worth Texas
Posts: 328
Thanks: 2
Thanked 8 Times in 8 Posts
iTrader Score: 0 reviews
That might have made up my mind, im going from stock and I always hear and read of others getting .5 to 2 mpg increase, but im not sure I believe them.

1992 Single Cab LB 4x4 5spd pump turned up a bit, custom intake, 4' DE Exhaust, DennyT Fuel Pin, 3.54 gears, leveled in front, JI Flatbed
(NEW) 1998 Ex. Cab LB 2500 4x4 5spd stock 12V w/132K Grail Truck
memphis04 is offline  
post #5 of 41 (permalink) Old 02-01-2013, 07:16 PM
Diesel Head
 
GAmes's Avatar
 
Join Date: Sep 2009
Location: Killeen, TX
Posts: 11,063
Thanks: 111
Thanked 1,304 Times in 1,126 Posts
iTrader Score: 7 reviews
Quote:
Originally Posted by memphis04 View Post
That might have made up my mind, im going from stock and I always hear and read of others getting .5 to 2 mpg increase, but im not sure I believe them.
For some reason there are those that feel the need to exaggerate the results of an aftermarket piece of equipment or to justify the cost of a fuel additive. If it really worked, considering the push for higher mileage vehicles and their salability, the factory would install them and the fuel companies would add them.

97 3500, 2 WD, G56, slightly bombed, 1.2 million miles. Started the second million on 8/24/13
If you are lucky enough to be in Texas, you are lucky enough.
GAmes is offline  
The Following User Says Thank You to GAmes For This Useful Post:
mattswaggs (02-04-2013)
post #6 of 41 (permalink) Old 02-01-2013, 07:30 PM
Diesel Head
 
Join Date: Nov 2005
Location: Montana
Posts: 16,224
Thanks: 27
Thanked 2,271 Times in 1,601 Posts
iTrader Score: 0 reviews
Quote:
For some reason there are those that feel the need to exaggerate the results of an aftermarket piece of equipment or to justify the cost of a fuel additive
It's because most folks don't want to admit they've been taken. I think some even truly believe they've had positive results.
Common benefit described is "the engine is quieter"
What the hell does that mean and what difference does it make?

Bill
'95 2500 4wd auto
'95 3500 5 speed heavy hauler
Stock for one day

Last edited by illflem; 02-01-2013 at 07:39 PM.
illflem is offline  
post #7 of 41 (permalink) Old 02-01-2013, 08:31 PM Thread Starter
Cummins Nut
 
memphis04's Avatar
 
Join Date: Nov 2007
Location: Fort Worth Texas
Posts: 328
Thanks: 2
Thanked 8 Times in 8 Posts
iTrader Score: 0 reviews
Yea I agree, I think the aftermarket cold air intakes, intake manifolds, and exhaust systems are quite a waste of money if your just cruising around in a daily driver. Please correct me if Im wrong.

1992 Single Cab LB 4x4 5spd pump turned up a bit, custom intake, 4' DE Exhaust, DennyT Fuel Pin, 3.54 gears, leveled in front, JI Flatbed
(NEW) 1998 Ex. Cab LB 2500 4x4 5spd stock 12V w/132K Grail Truck
memphis04 is offline  
post #8 of 41 (permalink) Old 02-02-2013, 01:31 AM
Diesel Head
 
country_hick's Avatar
 
Join Date: May 2011
Location: Maine
Posts: 10,772
Thanks: 6
Thanked 2,684 Times in 2,026 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by GAmes View Post
For some reason there are those that feel the need to exaggerate the results of an aftermarket piece of equipment or to justify the cost of a fuel additive. If it really worked, considering the push for higher mileage vehicles and their salability, the factory would install them and the fuel companies would add them.
Correct me if I am wrong here. Don't the newer diesel trucks come from factory with a 4" exhaust?

1997 3500 club cab 3.54 gears towing & camper pkg. Still stock with a built transmission at 120k. 4" exhaust, 4kgsk, and exhaust brake waiting for installation. 37337 upgrade. Still need ideas for improvements for hauling 15k fifth wheel.
country_hick is offline  
post #9 of 41 (permalink) Old 02-02-2013, 02:58 AM Thread Starter
Cummins Nut
 
memphis04's Avatar
 
Join Date: Nov 2007
Location: Fort Worth Texas
Posts: 328
Thanks: 2
Thanked 8 Times in 8 Posts
iTrader Score: 0 reviews
I had on 04 and it had factory 4 inch, but what would the advantage be?

1992 Single Cab LB 4x4 5spd pump turned up a bit, custom intake, 4' DE Exhaust, DennyT Fuel Pin, 3.54 gears, leveled in front, JI Flatbed
(NEW) 1998 Ex. Cab LB 2500 4x4 5spd stock 12V w/132K Grail Truck
memphis04 is offline  
post #10 of 41 (permalink) Old 02-02-2013, 08:35 AM
Diesel Head
 
GAmes's Avatar
 
Join Date: Sep 2009
Location: Killeen, TX
Posts: 11,063
Thanks: 111
Thanked 1,304 Times in 1,126 Posts
iTrader Score: 7 reviews
Quote:
Originally Posted by country_hick View Post
Correct me if I am wrong here. Don't the newer diesel trucks come from factory with a 4" exhaust?
The 3rd gens had 24 valve engines which move more air than a 12 valve, plus emissions stuff. The '04 HO was rated at 305 HP.

97 3500, 2 WD, G56, slightly bombed, 1.2 million miles. Started the second million on 8/24/13
If you are lucky enough to be in Texas, you are lucky enough.
GAmes is offline  
post #11 of 41 (permalink) Old 02-02-2013, 12:11 PM Thread Starter
Cummins Nut
 
memphis04's Avatar
 
Join Date: Nov 2007
Location: Fort Worth Texas
Posts: 328
Thanks: 2
Thanked 8 Times in 8 Posts
iTrader Score: 0 reviews
I just went out and measured mine and it was factory 4 inch? does yalls have that?

1992 Single Cab LB 4x4 5spd pump turned up a bit, custom intake, 4' DE Exhaust, DennyT Fuel Pin, 3.54 gears, leveled in front, JI Flatbed
(NEW) 1998 Ex. Cab LB 2500 4x4 5spd stock 12V w/132K Grail Truck
memphis04 is offline  
post #12 of 41 (permalink) Old 02-02-2013, 01:14 PM
Diesel Head
 
GAmes's Avatar
 
Join Date: Sep 2009
Location: Killeen, TX
Posts: 11,063
Thanks: 111
Thanked 1,304 Times in 1,126 Posts
iTrader Score: 7 reviews
Quote:
Originally Posted by memphis04 View Post
I just went out and measured mine and it was factory 4 inch? does yalls have that?
Did you just measure the tip? The stock exhaust expands to 4" at the end.

97 3500, 2 WD, G56, slightly bombed, 1.2 million miles. Started the second million on 8/24/13
If you are lucky enough to be in Texas, you are lucky enough.
GAmes is offline  
Sponsored Links
Advertisement
 
Closed Thread

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Dodge Cummins Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome