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  #13  
Old 11-24-2013, 01:39 AM
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Re: One More Hemi Fuel Economy Thread

Sounds like you're well on your way to getting it squared away.

Some folks can "get away with" running platinum or iridium plugs, but they are not recommended. Many other folks have encountered misfires after installing the "better" plugs. I just stick with a good copper core and change them every 30K, as specified in the FSM. I've got SOS coils on mine now and run the plug gaps at .060-.065 in.

The normal air filter shouldn't cause you any grief around town, but may have a slight effect on the highway. I've got a couple stock filters laying around and put one on my Hemi LX and then took a 1000 mile trip. Don't know if it was the total cause of lower fuel economy, but I was down almost one mpg from normal for it.

If the EGR is bad or going bad you'll start getting erratic, rough, sometimes almost stalling idle, low speed (~35-45 mph) surging, and poor fuel economy and performance. You may not always get a DTC either, unless it's real bad.
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05 LX/RT & 06 WK/GCO, modded similarly, MDS "ON" Light, Vortex Gens, Debadged, DashHawk, BT Catch Can, SRT CAI W/Add Air Inlet, K&N Filter, Sonnax Trans Press Booster, SC Tuner W/Adv Trans Tuning App, DS Tuner, Cust tube headers w/3 in. catback, Bilsteins, SRT frt/rear bumpers, Eibach SRT Lwr Sprgs & Sways, FRI Sidewinder Cam Adv 2*, 6.1 valvetrain, SLP 25% UD Pulley, BBK 90mm TB, SOS Coils/.060 plug gaps. 20 in. SRT Reps.
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  #14  
Old 11-24-2013, 07:38 AM
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Re: One More Hemi Fuel Economy Thread

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Originally Posted by jeepgcoman View Post
Sounds like you're well on your way to getting it squared away.

Some folks can "get away with" running platinum or iridium plugs, but they are not recommended. Many other folks have encountered misfires after installing the "better" plugs. I just stick with a good copper core and change them every 30K, as specified in the FSM. I've got SOS coils on mine now and run the plug gaps at .060-.065 in.
Works for me. I'm all for saving the $1 a plug to go with copper. Since i posted I found an old service form that showed the plugs were change 28K ago, so I'm right on time for new plugs.
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Old 11-24-2013, 07:20 PM
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Plugs and New EGR are in. Not to bad of an install just took time. I got a K&N filter too since the plugs got me $20 off at AutoZone.
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Old 11-25-2013, 11:00 AM
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Re: One More Hemi Fuel Economy Thread

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Plugs and New EGR are in. Not to bad of an install just took time. I got a K&N filter too since the plugs got me $20 off at AutoZone.
I think its time for some seafoam. Here is a shot of the throttle body from when I was doing the plugs.
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File Type: jpg 08-WK-Intake1.jpg (94.6 KB, 10 views)
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Old 11-25-2013, 03:34 PM
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Re: One More Hemi Fuel Economy Thread

That's pretty typical, but not as bad as some we've seen on these forums. With a catch can, at best you'll just get a very slight film on the TB that is easily wiped off with a rag. Also, look behind the TB into the intake manifold plenum to see if there is any puddling. If there is, you may want to consider removing it and do a complete clean.
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  #18  
Old 11-25-2013, 04:15 PM
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Re: One More Hemi Fuel Economy Thread

Quote:
Originally Posted by jeepgcoman View Post
That's pretty typical, but not as bad as some we've seen on these forums. With a catch can, at best you'll just get a very slight film on the TB that is easily wiped off with a rag. Also, look behind the TB into the intake manifold plenum to see if there is any puddling. If there is, you may want to consider removing it and do a complete clean.
Good to know I'm at least about on par.
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Old 11-27-2013, 08:47 PM
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Re: One More Hemi Fuel Economy Thread

After a full day of driving all highway at 70mph ish, the math worked out to 15.86mpg.
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Old 11-27-2013, 10:38 PM
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Re: One More Hemi Fuel Economy Thread

That's really not all that bad for the speed.....maybe only slightly low. I just did a 150 mile trip yesterday, driving ~75-80 mph (I usually drive ~60-65 mph), and it costs almost 3 mpg to drive faster. On this run I usually get right at 23 mpg, and this time it was only a little over 20 mpg. So much impacts the mileage....tire pressure, wind, terrain, altitude, etc., and even the surface you're driving on. With my DashHawk I can watch engine load (%age) and it'll change sometimes ~2-5% when the road surface changes, say from a course asphalt to a smooth concrete or asphalt or vise versa. Pretty amazing to watch. Another one that surprised me a little is the load difference when a truck is in various stages of passing me, or especially if I get in a truck's slip stream.
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05 LX/RT & 06 WK/GCO, modded similarly, MDS "ON" Light, Vortex Gens, Debadged, DashHawk, BT Catch Can, SRT CAI W/Add Air Inlet, K&N Filter, Sonnax Trans Press Booster, SC Tuner W/Adv Trans Tuning App, DS Tuner, Cust tube headers w/3 in. catback, Bilsteins, SRT frt/rear bumpers, Eibach SRT Lwr Sprgs & Sways, FRI Sidewinder Cam Adv 2*, 6.1 valvetrain, SLP 25% UD Pulley, BBK 90mm TB, SOS Coils/.060 plug gaps. 20 in. SRT Reps.
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