Fuel savings from cat back exhaust and/or cold air intake
#1
Fuel savings from cat back exhaust and/or cold air intake
Just curious if any of you with these mods have noticed fuel mileage increases with them in addition to the power increase? If so would you ost the reported savings? I am mostly interested in the difference it makes for a 3.7 L V-6.
#2
RE: Fuel savings from cat back exhaust and/or cold air intake
I have both of those (K&N FIPK and Magnaflow) along with Superchips and a Fastman TB and I haven't noticed any real increase or decrease in mileage. I do notice it comes off the line quicker and between 3-4000rpm it pulls harder than it did. I should also note that I have an '03 4.7L QC and not a V6. I have been running the towing setting on the Superchips just for more torque down low and running premium fuel. If gas keeps going up, I will probably switch the Superchips programming to 87 performance. Hope that helped.
#3
RE: Fuel savings from cat back exhaust and/or cold air intake
The biggest difference I got was when I got rid of the mechanical fan and installed an electric fan. My mileage went from 12.5 to 15 mpg. I mostly average around 14mpg and I do all city stop and go driving. I have the V8 and have the cold air intake, gibson exhaust, Fastman throttle body.
#4
#5
RE: Fuel savings from cat back exhaust and/or cold air intake
ORIGINAL: Outdoorsman5953
Just curious if any of you with these mods have noticed fuel mileage increases with them in addition to the power increase? If so would you ost the reported savings? I am mostly interested in the difference it makes for a 3.7 L V-6.
Just curious if any of you with these mods have noticed fuel mileage increases with them in addition to the power increase? If so would you ost the reported savings? I am mostly interested in the difference it makes for a 3.7 L V-6.
#6
RE: Fuel savings from cat back exhaust and/or cold air intake
There will be no 'real' MPG savings from a CAI
but by random chance
half of all CAI buyers will see a change either higher or lower
on the next tank.
If you think a CAI will allow the engine to 'breathe better'
and get improved MPG
you need to study how the throttle on a gasoline engine works
what MAP is
and how MAP is what determines what hp a gasoline engine makes.
The cat back exhaust will improve MPG slightly if it reduces the backpressure at the exhaust valve port, but in typical driving at partially closed throttle the backpressure in the exhaust will be low...in the half to one PSI range because the engine does not have to make much exhaust flow....much much less than at full throttle and high rpm.
This will rise to around 7 psi or more at full throttle.
You can measure exhaust backpressure with simple gauges bought at auto stores or JC Whitney.
http://www.sjdiscounttools.com/waebpt01.html
In 18 wheel trucks where tiny fuel cost savings is a profit/bankruptcy thing
the muffler makers provide big companies like Walmart/JB Hunt/UPS plenty of information to justify the small MPG gain:
http://www.walkerheavyduty.com/walke...page=muf_noise
You are FAR MORE likely to get a worthwhile MPG gain
by changing tires than by exhaust changes:
http://www.us.pirelli.com/web/techno...e/default.page
various new tires greatly vary in rolling resistance
and it can make a 1 to 2 MPG difference when brand new
and this can change as the tread depth wears down
and the tire psi
can make also 0.5 to 1 MPG difference.
but by random chance
half of all CAI buyers will see a change either higher or lower
on the next tank.
If you think a CAI will allow the engine to 'breathe better'
and get improved MPG
you need to study how the throttle on a gasoline engine works
what MAP is
and how MAP is what determines what hp a gasoline engine makes.
The cat back exhaust will improve MPG slightly if it reduces the backpressure at the exhaust valve port, but in typical driving at partially closed throttle the backpressure in the exhaust will be low...in the half to one PSI range because the engine does not have to make much exhaust flow....much much less than at full throttle and high rpm.
This will rise to around 7 psi or more at full throttle.
You can measure exhaust backpressure with simple gauges bought at auto stores or JC Whitney.
http://www.sjdiscounttools.com/waebpt01.html
In 18 wheel trucks where tiny fuel cost savings is a profit/bankruptcy thing
the muffler makers provide big companies like Walmart/JB Hunt/UPS plenty of information to justify the small MPG gain:
http://www.walkerheavyduty.com/walke...page=muf_noise
You are FAR MORE likely to get a worthwhile MPG gain
by changing tires than by exhaust changes:
http://www.us.pirelli.com/web/techno...e/default.page
various new tires greatly vary in rolling resistance
and it can make a 1 to 2 MPG difference when brand new
and this can change as the tread depth wears down
and the tire psi
can make also 0.5 to 1 MPG difference.
#7
RE: Fuel savings from cat back exhaust and/or cold air intake
ORIGINAL: HankL
various new tires greatly vary in rolling resistance
and it can make a 1 to 2 MPG difference when brand new
and this can change as the tread depth wears down
and the tire psi
can make also 0.5 to 1 MPG difference.
various new tires greatly vary in rolling resistance
and it can make a 1 to 2 MPG difference when brand new
and this can change as the tread depth wears down
and the tire psi
can make also 0.5 to 1 MPG difference.
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#8
RE: Fuel savings from cat back exhaust and/or cold air intake
I can't agree with above post.
Today the only way to know tire rolling resistance is to measure it...
you can't tell by weight, look, tread pattern
because the technology of the rubber is rapidly changing.
Look over some of the posted web links here:
https://dodgeforum.com/forumid_167/tt.htm
such as this recent one from Michelin
publicly promising big improvements:
https://dodgeforum.com/m_1028702/tm.htm
Today the only way to know tire rolling resistance is to measure it...
you can't tell by weight, look, tread pattern
because the technology of the rubber is rapidly changing.
Look over some of the posted web links here:
https://dodgeforum.com/forumid_167/tt.htm
such as this recent one from Michelin
publicly promising big improvements:
https://dodgeforum.com/m_1028702/tm.htm
#9
RE: Fuel savings from cat back exhaust and/or cold air intake
Not only that but how far do you have to drive to get your money back. I figured if I put in $250 to get a 1 mpg increase I'd have to drive 27,000 miles to recoupe the investment.
But at these gas prices I'm finally justifying the insurance for riding my Concours.
But at these gas prices I'm finally justifying the insurance for riding my Concours.