mpg impact - Jeep Commander Forums: Jeep Commander Forum
Exhaust Questions or advice about exhaust systems? This is the place...

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 12 (permalink) Old 04-28-2011, 09:46 AM Thread Starter
Member
Points: 3,738, Level: 38 Points: 3,738, Level: 38 Points: 3,738, Level: 38
Level up: 59% Level up: 59% Level up: 59%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Apr 2011
Posts: 31
mpg impact

I am looking at all ways to improve my MPG (2006 5.7). I have read many claims that an after market exhaust system combined with a CAI will get me 1-2 MPG. From those that have done it what is the actual measured impact if any. Please try to respond with the facts as I don't want to waste money. thanks guys.
xkcommander is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 04-28-2011, 11:14 AM
Senior Member
Points: 9,538, Level: 65 Points: 9,538, Level: 65 Points: 9,538, Level: 65
Level up: 63% Level up: 63% Level up: 63%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Dec 2010
Location: Lisle, IL
Own a Commander?: Yes
Model year: 2007
Trim Package: Overland
Power-Train: 5.7L V-8 Hemi
4WD
If 4WD - system: QD-II
Current Mileage: 126000
Posts: 417
The facts are this: do the math when considering expensive add-ons only for fuel savings. It's called and ROI (return on on investment) analysis.

Basically, it will take you a certain amount of time to make up for the expense of buying the performance equipment that may (or may not) get you better mileage. Keeping in mind that when you put go-fast parts on your car, your tendency will be to try them out - negating any savings you were expecting.

Intake, exhaust and programmer are the most popular bolt-ons that help your engine work more efficiently. Let's say they cost you $1000 and they save you 1 mpg.

At $4 per gallon of gas and going from an average of 12 mpg to 13 mpg and driving an average of 1000 miles per month:

$4 per gal @12mpg for 1000 miles per month = 83.33 gal
$4 per gal @13mpg for 1000 miles per month = 76.92 gal

A difference of 6 gallons per month

6 gallons x $4 = $24 per month savings

Initial investment ($1000) / $24 month = 41.66 months to recoup your initial investment.

Then there's the free way. Keep your tires inflated, your vehicle serviced, lighten your load and drive like a grandma. You'll probably still see the 1 mpg (or more) improvement.


I am now stepping down off my soap box.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


2007 Overland with all the options (including boulder-kissed bumper)
Bobula is offline  
post #3 of 12 (permalink) Old 04-28-2011, 11:35 AM
Senior Member
Points: 8,101, Level: 60 Points: 8,101, Level: 60 Points: 8,101, Level: 60
Level up: 76% Level up: 76% Level up: 76%
Activity: 0% Activity: 0% Activity: 0%
 
Matt_'s Avatar
 
Join Date: Jun 2010
Location: NJ
Posts: 1,128
How many miles are on your XK? Given the model year I'm sure you're due (or over due) for spark plugs. They're supposed to be replaced every 30k miles.

I saw a 3mpg improvement when I put fresh plugs in. (I'm also fairly certain that the previous owner only used mine for city driving, so it was a hard 24k miles when they owned it).

So if you haven't had it done..... fresh plugs, new tcase and diff fluids are due and will definitely help out with MPG.

If you are up to date with maintenance, don't buy an intake for gas mileage.......unless that's just the excuse you're using so your wife lets you.

-Matt
Matt_ is offline  
 
post #4 of 12 (permalink) Old 04-28-2011, 11:38 AM Thread Starter
Member
Points: 3,738, Level: 38 Points: 3,738, Level: 38 Points: 3,738, Level: 38
Level up: 59% Level up: 59% Level up: 59%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Apr 2011
Posts: 31
Soapbox

Your statements are accepted and understood.

What I am looking for is better range and the money does not matter that much as long as it makes a 1-2mpg improvement.

You see in Africa we can be 100's of miles away from fuel and there is only so much you can carry given I already need 2 spares etc etc etc.

Even 1 extra mpg*40 gallon's can mean the difference between walking though the bush for 40 miles to get fuel (and maybe getting eaten - no joke) or not.

thanks for your input.

xkcommander is offline  
post #5 of 12 (permalink) Old 04-28-2011, 11:49 AM
Senior Member
Points: 8,101, Level: 60 Points: 8,101, Level: 60 Points: 8,101, Level: 60
Level up: 76% Level up: 76% Level up: 76%
Activity: 0% Activity: 0% Activity: 0%
 
Matt_'s Avatar
 
Join Date: Jun 2010
Location: NJ
Posts: 1,128
Lol well that does change perspective a bit!

Here's what I recommend:
1) make sure you're up to date on maintenance.
2) get a programmer like supechips and run the efficiency tune.
3) get a set of good LRR Rated tires (low rolling resistance). If you can't get LRR tires, get a standard tread design and target lighter weight.

-Matt
Matt_ is offline  
post #6 of 12 (permalink) Old 04-28-2011, 11:59 AM Thread Starter
Member
Points: 3,738, Level: 38 Points: 3,738, Level: 38 Points: 3,738, Level: 38
Level up: 59% Level up: 59% Level up: 59%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Apr 2011
Posts: 31
Agreed

Got the superchips, got the correct oil. Tyres are OK but off road often have to deflate anyway. Looking for a bit more thats all. I don't want to go down the CAI and exhaust path only to have it make no difference.

thanks again
xkcommander is offline  
post #7 of 12 (permalink) Old 04-28-2011, 12:16 PM
Senior Member
Points: 9,538, Level: 65 Points: 9,538, Level: 65 Points: 9,538, Level: 65
Level up: 63% Level up: 63% Level up: 63%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Dec 2010
Location: Lisle, IL
Own a Commander?: Yes
Model year: 2007
Trim Package: Overland
Power-Train: 5.7L V-8 Hemi
4WD
If 4WD - system: QD-II
Current Mileage: 126000
Posts: 417
Ohhh, you want range. I can understand why.

This is really the only definite fix for that.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


2007 Overland with all the options (including boulder-kissed bumper)
Bobula is offline  
post #8 of 12 (permalink) Old 04-28-2011, 12:25 PM
Senior Member
Points: 9,538, Level: 65 Points: 9,538, Level: 65 Points: 9,538, Level: 65
Level up: 63% Level up: 63% Level up: 63%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Dec 2010
Location: Lisle, IL
Own a Commander?: Yes
Model year: 2007
Trim Package: Overland
Power-Train: 5.7L V-8 Hemi
4WD
If 4WD - system: QD-II
Current Mileage: 126000
Posts: 417
You say you have 40 gallons. Where is that coming from? The only for sure way to get better range (I would not feel safe doing the 1 mpg thing) is to hold more fuel. Most do it with Jerry cans (or 4 as mentioned above) Some have put spare tanks adding 30 gallons. Of course, that fits in the spare wheel well and subtracts one place for one of your spare tires to fit.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


2007 Overland with all the options (including boulder-kissed bumper)
Bobula is offline  
post #9 of 12 (permalink) Old 04-28-2011, 12:31 PM Thread Starter
Member
Points: 3,738, Level: 38 Points: 3,738, Level: 38 Points: 3,738, Level: 38
Level up: 59% Level up: 59% Level up: 59%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Apr 2011
Posts: 31
Plugs & Fuel

Yes I am overdue for plugs. Stealer would not do it at the last service even though it is due. Re fuel - I carry Jerry cans and there is a limit to what I can handle with all the other stuff. Thanks for the feedback. Does anyone have a measured impact of exhaust and CAI?

cheers
xkcommander is offline  
post #10 of 12 (permalink) Old 04-28-2011, 12:59 PM
Super Moderator
Points: 59,055, Level: 100 Points: 59,055, Level: 100 Points: 59,055, Level: 100
Level up: 0% Level up: 0% Level up: 0%
Activity: 100% Activity: 100% Activity: 100%
 
jeep5253's Avatar
 
Join Date: Jun 2006
Own a Commander?: Yes
Model year: 2006
Trim Package: Limited
Power-Train: 5.7L V-8 Hemi
4WD
If 4WD - system: QD-II
Posts: 14,853
Quote:
Originally Posted by xkcommander View Post
Does anyone have a measured impact of exhaust and CAI?
cheers
Trust me...they won't make enough difference for you bother with.

2006 Steel Blue 5.7L HEMI Limited 4x4 Build Date: June 9, 2006 Hour 14
Interior: Dark Slate/Light Graystone with Saddle Brown Leather Seats
Quadra-Drive II, NAV, DVD, Trailer Tow Group IV, Off-Road Group II, Remote Start, UConnect, Rear Backup Camera, Chrome Wheels,
Magnaflow cat-back exhaust, Daytime Running Lights enabled, 2" Rough Country Lift with 265/70R17 Goodyear Wrangler AT/S
jeep5253 is offline  
Sponsored Links
Advertisement
 
Reply

  Jeep Commander Forums: Jeep Commander Forum > Jeep Commander Discussion > Performance Modifications > Exhaust

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Jeep Commander Forums: Jeep Commander 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











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not 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