MPG Loss

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MPG Loss

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MPG Loss - 7/3/2008 6:26:03 PM

Poke In Da Eye

Posts: 9
Joined: 4/23/2008
Status: offline

I installed a Magnaflow dual exhaust along with a Diablo Sport Predator programer (performance tune), MPG increased 2.4 MPG, I installed a K&N CIA (off road) and MPG went back to 12.5 on hiway @ 70 MPH, 13.5 @ 65 MPH....... Any ideas???

I spent over $1,000 did not realize any increase in MPG, there was in increase in performance..... Note, my wife was driving and she IS NOT an agressive driver.....

In addition, will converting to JBA headers increase MPG.....

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03 H2 Pewter - "100th Anniversary Edition Harley Davidson" (Added HD badges all over)
Brush guard, Bumpers & Nerf bars "Rhino Lined"
06 Limited Edition wheels & Side mirrors
Custom Magnaflow BLOCK Back - 3" in/3" out dual exhaust

Post #: 1

RE: MPG Loss - 7/3/2008 6:35:23 PM

Marauder

Posts: 27
Joined: 6/28/2008
Status: offline

As you add more air, your computer will automatically add more fuel to maintain a given a/f (air fuel) ratio. When you added exhaust, you didnt add more air coming INTO the engine so it went up because it had more free flow out.

(in reply to Poke In Da Eye)

Post #: 2

RE: MPG Loss - 7/4/2008 7:50:40 AM

Hummer Dog

Posts: 57
Joined: 5/16/2008
Status: offline

The K&N CAI may have changed the MAF table, if that''s the case, about the only way you can fix it is with EFILive and a flowbench.

(in reply to Marauder)

Post #: 3

RE: MPG Loss - 7/4/2008 7:55:21 AM

Intercooled

Posts: 253
Joined: 7/18/2005
Status: offline

quote:

ORIGINAL: Poke In Da Eye

I installed a Magnaflow dual exhaust along with a Diablo Sport Predator programer (performance tune), MPG increased 2.4 MPG,

2.4 mpg increase! Thats pretty good for an exhaust and performance tune. I may have to consider doing that. Where is the Performance Tune available from? is it just plug and play?

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1987 Buick GN
2006 H2 SUT Fusion Orange LE

(in reply to Poke In Da Eye)

Post #: 4

RE: MPG Loss - 7/4/2008 8:22:26 PM

HummBob

Posts: 16165
Joined: 5/6/2006
Status: offline

I got about a 2.8 increase after I did my Volant CAI and Magnaflow Exhaust!!

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2004 Black Hummer H2

2007 Black Escalade

(in reply to Intercooled)

Post #: 5

RE: MPG Loss - 7/5/2008 10:40:56 AM

pteam

Posts: 125
Joined: 1/29/2008
Status: offline

so you guys are going from 12s mpg to 15s mpg?

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(in reply to HummBob)

Post #: 6

RE: MPG Loss - 7/5/2008 7:15:53 PM

HummBob

Posts: 16165
Joined: 5/6/2006
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quote:

ORIGINAL: pteam

so you guys are going from 12s mpg to 15s mpg?

10.1 to 12.9

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2004 Black Hummer H2

2007 Black Escalade

(in reply to pteam)

Post #: 7

RE: MPG Loss - 7/5/2008 10:44:44 PM

08H2SUT

Posts: 13
Joined: 6/23/2008
Status: offline

You can increase your MPG by 1 if you remove the screen between your maff and your filter. Only GM uses them, and I dont know why. All i know it to do is restrict the air flow. I havent had any problems with my H2 since I removed it. Did the same to an ''07 Tahoe that I sold and never had any problems. It might add a little power, but its minimal, so you probably wont feel anything. Not sure if the earlier models hae them either. Hope it helps.

(in reply to HummBob)

Post #: 8