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Unread 06-27-2012, 10:01 PM   #1
Shafer57
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12.5 Average MPG?

06' Hemi. Mostly back roads 35 mph speeds stop and go every so often. But I still think 12.5 is a very low number, i've hit the reset button but still it goes right back to the 11.5-13.0 mark.

Currently have a K&N full intake, tires at 33-35 psi, 89 octane BP fuel, A/C rarely used.

What are some of the major things i should be doing? I'm somewhat new to the Hemi so not 100% sure what the immediate things to look for are. I bought the truck around 10 months ago certified pre-owned.


ALL opinions and suggestions are appreciated in advance

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Unread 06-27-2012, 10:06 PM   #2
kllshadow
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That is about what I get. You bought a HEMI its job is to dump fuel in and give you power. The lack of Aerodynamics doesn't help either.
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Unread 06-27-2012, 10:18 PM   #3
90grandoneer
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How many miles on it, and what is the maintenance status....spark plugs, filters, fluid changes, trans. service, etc.?
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Unread 06-27-2012, 10:23 PM   #4
S1L3NT_WH33L3R
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I made 14when I first got mine then my mom got an 06 and she makes the same thing.
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Unread 06-27-2012, 10:36 PM   #5
Static83
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better then my 11 on my 4.7
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Unread 06-28-2012, 09:18 AM   #6
fourtrax450r
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i have an 07 drops to 4 cyl running 93octane at 40psi. bad alignment and i like to play with the throttle a bit and get 16.5 mph. learn to feather that gas, get an alignment, and run 40psi in your tires, but thats only if you drop 4 cylinders.
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Unread 06-28-2012, 09:32 AM   #7
Shafer57
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Not complaining about the MPG, just confirming that this is normal and there's no issues. My old Dakota with the 360 did worse

Spark plugs done 5K ago (standard copper tops) and injector cleaner ran every 6K. Oil changes every 3,500 semi-syn, I have some of the old maintenance records but nothing really more than brakes and oil changes.
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Unread 06-28-2012, 09:40 AM   #8
fourtrax450r
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i understand but im saying you can achieve much better. people who are okay with 12 mpg when they can achieve 16 are lazy. i was that guy and then a month ago i said no...i want better gas mileage lol
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Unread 06-28-2012, 09:47 AM   #9
AJeepZJ
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Quote:
Originally Posted by fourtrax450r View Post
i understand but im saying you can achieve much better. people who are okay with 12 mpg when they can achieve 16 are lazy. i was that guy and then a month ago i said no...i want better gas mileage lol
agree 100%. unless you are living in a high-altitude state, you are wasting money, gas, and can actually be ignoring a symptom of something more important. A lot of stuff effects the MPG, and the HEMI is a complex engine - it's not always as simple as checking spark plugs, air filter, and tire pressure.
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Unread 06-28-2012, 10:06 AM   #10
fourtrax450r
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also, check if your MDS even works. i have a guy who couldnt figure out why he was getting 10 mpg when he realized his motor was stuck in tow/haul mode. it changes the shift points and eliminated MDS PLUS maps the A/F ratio to something you dont even want to know.
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Unread 06-28-2012, 10:45 AM   #11
andrew44
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Spend some money and chip it. Wake that hemi up a little
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Unread 06-28-2012, 10:58 AM   #12
06WKHEMI
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I just ordered my flash paq from kolak yesterday what a deal I can't wait to install it
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Unread 06-28-2012, 11:15 AM   #13
Shafer57
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Have a Diablosports Predator but I set it back to factory settings from the performance tune to see if that resolved my issue a bit.

But like most of you have said; I'm looking to figure out if there's an actual problem versus routine maint. issues.

What is an EGR, and does this effect my mileage? becuase no-where in the records does it say it's been replaced. It has 74,500K on it.

Your answers have been helpful so far
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275/45R20 Nexen Roadian, Blacked out, 180 Stat _SOLD_
2008 335i Twin-Turbo
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Unread 06-28-2012, 11:23 AM   #14
fourtrax450r
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im looking for a good tune but im scared to get one to be honest. looking for something with a few different mappings, and maybe customizable. i want maximum fuel efficiency on one, and max horsepower on another as well as stock.
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Unread 06-28-2012, 11:28 AM   #15
90grandoneer
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The Exhaust Gas Recirculation Valve (EGR), is located on the front, passenger side head and has an insulated tube going to the intake manifold. If this valve malfunctions, some of the symptoms are, erratic, almost stalling idle, low speed surging, and poor performance and fuel economy. Mine went bad (with a code) at ~54K miles. When is the last time the plugs were changed? What type of plugs were installed? Has the backside of the throttle body butterfly been cleaned? Do you have a catch can? If not, IMO, it is a must on the Hemi. Take the air tube off at the throttle body and manually (with engine off) open the butterfly. Shine a light in and examine the backside of the butterfly and the intake plenum behind it. Look for caked on oil crap, and puddling in the plenum. Guaranteed you'll have it, and it will probably be real bad. This crap may affect the proper operation of the MAP Sensor, which in turn will tank the fuel economy. When's the last time the PCV Valve was changed? Once all of this is sorted out and repaired/replaced, reinstall the DS Tuner. It should work real well....it does on mine.
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06 GCO, Dk Khaki, QDII, Flshing Hi 3rd Bk Lt, MDS "ON" Lt, Airtab Vortex Gens, Debadged, Fumoto Drain Valve, BT Catch Can, Chopped EGR Tube, SRT8 CAI, K&N Filter, Sonnax Trans Line Press Booster, SC Tuner W/Adv Trans Tune App, DS Tuner, Cust tubular hdrs w/3 in Magnaflow/Xlerator AP Exh Sys, Bilsteins, SRT Springs/Sways, Cust Eng Cvr, SRT8 frt/rear bumpers, FRI Sidewinder Cam/6.1 valvetrain, SLP 25% UD Pulley, BBK true 90mm T-Body, SOS Ign Coils w/.060 spark plug gaps, SRT Reps with 265/45&295/40X20's.
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