Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (http://www.jeepgarage.org/forums.php)
-   Engine Performance/Intake/Exhaust (http://www.jeepgarage.org/f183/)
-   -   Mods made a difference (http://www.jeepgarage.org/f183/mods-made-a-difference-42620.html)

Speedtech 05-27-2012 09:57 AM

Mods made a difference
 
Well after everything is said and done with the addition of the Airaid intake tube, and the cat-back exhaust, was a Flowmaster system but I swapped the muffler for a Walker Quietflow SS #21054, and a Predator 91 octane tune with trans adapts I found in the thread started by Blackpepper. I gave the Hemi Jeep the test last night. On my usual 70 mile drive to the racetrack every Saturday I keep track of my fuel usage. On this weeks trip with all the mods finally installed I got 1.5 MPG's better than last week, and this week I had the A/C on most of the time, so I bet it is close to a 2 MPG improvement. That is including several instances of dropping the hammer to pass a few cars. So with the A/C on driving at 63 MPH most of the time in upstate NY wich is anything but flat my Hemi got 18.8 MPG for the entire trip, about 70 miles each way. I am happy, better mileage (if you control yourself), better power, and better sound. Just need some Bilsteins and Eibachs and I am all set.

Chaoul1 05-27-2012 11:23 AM

Re: Mods made a difference
 
Was your Jeep packed with things inside of it? I can average 20-21 MPG's going 75MPH with two people and a few things in the rear cargo. That's without a Tune. I haven't tried my Gas Saver Tune on my Diablo Sport.

Speedtech 05-27-2012 08:40 PM

Re: Mods made a difference
 
Quote:

Originally Posted by Chaoul1 (Post 635328)
Was your Jeep packed with things inside of it? I can average 20-21 MPG's going 75MPH with two people and a few things in the rear cargo. That's without a Tune. I haven't tried my Gas Saver Tune on my Diablo Sport.

I have seen mileage claims like yours from others as well. I have never seen my Jeeps mileage above 17.4 MPG's to 17.6 MPG's on a sustained trip until last night then it was 18.8 MPG when I got to the racetrack, it was 18.4 MPG's when I got home. My around town mileage is really bad 12-13 MPG area. Strange thing is I seem to have noticed a drop in city mileage after I cleaned my throttle body, I did this before seeing the warnings against it and before I found this forum, that one is puzzling to me. My Hemi Jeep gets close to my GF's 2000 Cherokee's mileage.

mTBrunner83 05-29-2012 06:57 PM

Re: Mods made a difference
 
I average 17 mpg in my 3.7L around town and some highway travel combined. In the city I do not suffer as much as a Hemi (I imagine it is due to the excess power in stop and go situations), but on the highway I cannot match the efficiency of the Hemi that can easily pull itself along at speeds in excess of 60 mph and run faster at lower rpms not making the engine work nearly as hard. After tuning your vehicle you just have to find the sweet spot. If I am gentle I can get 19.2 overall average, but this is not realistic to the nature of my driving. In the city I easily average 17. But even on highway trips the best I can do unless everything was just flat and I was going 60-62 mph the entire time is 19 or so. The 3.7L just has to work much harder than the Hemi to keep it going 70mph. The 6 cylinder and the heavy Jeep do not always make a fair match. If I could do this all over I may have considered the 4.7L at minimum... maybe. As I do more in city driving the 3.7L has allowed me to be more efficient on the gas. I am no expert on this however so I could be off base here. I can only offer observation.

05WK 06-08-2012 10:58 PM

Re: Mods made a difference
 
Quote:

Originally Posted by Speedtech (Post 635310)
Well after everything is said and done with the addition of the Airaid intake tube, and the cat-back exhaust, was a Flowmaster system but I swapped the muffler for a Walker Quietflow SS #21054, and a Predator 91 octane tune with trans adapts I found in the thread started by Blackpepper. I gave the Hemi Jeep the test last night. On my usual 70 mile drive to the racetrack every Saturday I keep track of my fuel usage. On this weeks trip with all the mods finally installed I got 1.5 MPG's better than last week, and this week I had the A/C on most of the time, so I bet it is close to a 2 MPG improvement. That is including several instances of dropping the hammer to pass a few cars. So with the A/C on driving at 63 MPH most of the time in upstate NY wich is anything but flat my Hemi got 18.8 MPG for the entire trip, about 70 miles each way. I am happy, better mileage (if you control yourself), better power, and better sound. Just need some Bilsteins and Eibachs and I am all set.

What's your total mileage on the jeep? This may be the cause of your mpg's being lower than usual

jeepgcoman 06-09-2012 10:17 PM

Re: Mods made a difference
 
^^^^ True! Probably 95% of my driving is at altitudes between 2500-4000 ft. in all hilly/mountainous terrain, and when mine was totally stock my best was 18 mpg. Since finishing my mods., I have not gotten less than 20 mpg on the highway (~60-65 mph) and usually get 21-22 mpg. Best so far, at altitude, is 23 mpg. In town, with lots of heavy foot activity, I usually get between 13-14.5 mpg, depending on the amount of stop and go.

On yours, Speedtech, if you have lots of miles on it, I think I'd be checking O2 sensors, MAP sensor, and especially the spark plugs. If it's an 05 Hemi, check the plug wires too. If you're not using synthetic oil, most say that using it helps a little too.

05WK 06-09-2012 11:22 PM

Re: Mods made a difference
 
If you haven't already, I'd do

Transmission service
Spark plugs and cables
And sea foam the entire jeep, oil and gas

Speedtech 06-10-2012 08:00 PM

Re: Mods made a difference
 
I have had this Jeep since new, it has 80K on it now, I put in NGK Iridium IX's at 30K, Royal Purple in the diffs at 45K, trans filters and total fluid exchange at 75K, T-case fluid about 40K, Mobil 1 every 5K since new, frequent use of Lucas fuel treatment, she is a runner and well maintained. Mileage has always been at best 18 on the highway at 70MPH, not much better at 65MPH. Since the Mods I have seen it over 20 on the highway. I do not have a HEMI Jeep by mistake I have a lead foot, I have seen improvement in my MPG. My Jeep only has a 5 speed transmission are some of the later WK's 6 speeds?? I see some of the mileage claims and they are much better than I think I could ever get.

05WK 06-10-2012 11:07 PM

Re: Mods made a difference
 
Sea foam my friend.. as good as Lucas is, sea foam will instantly kick all that shiz out and steadly through the fuel.

Give it a shot. Im at 100K and i saw little smoke, but thats still something that was in there clogging stuff up!

brentwoodkris 06-12-2012 12:45 PM

Re: Mods made a difference
 
Quote:

Originally Posted by Chaoul1 (Post 635328)
Was your Jeep packed with things inside of it? I can average 20-21 MPG's going 75MPH with two people and a few things in the rear cargo. That's without a Tune. I haven't tried my Gas Saver Tune on my Diablo Sport.

Holy crap. I'm lucky if I get around 18-18.5 on an average 120 mile highway trip...apparently I need something to help that...

Transmission service is on the list of things for me to do. I've never been comfortable with doing that seafoam thing everyone says to do, weirds me out.

Kayak83 06-12-2012 05:15 PM

Re: Mods made a difference
 
I'm really happy if I get 18 on the highway around here but we have HILLS...

Going over the mountain passes on a 2+ hour trip it's more like 15-16. In city (Seattle area) it's more like 13. If I stay on flat highway for 2+ hours it's 18-21 mpg.

Lots of "mpg" mods and relatively low mileage on my WK. I don't think mine is in any need of new sensors, etc. either.

05WK 06-12-2012 06:17 PM

Re: Mods made a difference
 
Brentwoodkris, idk why it wields you out... It's just like any other injector cleaner. And its a total engine treatment.

You put some in the gas to clean the fuel system.
You put some in the oil, a few hundred miles before the oil is due to be changed.
And the final bit may require two people. When the engine is warm, you take the brake vac line off and feed in a little bit of SF as someone keeps the engine at 2K rpms. White smoke will come out for a bit then you let rest for about 20 minutes. Then you drive it hard!(legally) around for a bit usually until the smoke

After doing this mine ran amazing. I could instantly tell the difference in the idle and the smoothness of the engines performance. Mine didn't smoke very much but it definatly cleaned it out

Nothing to be scared of :D
Give it a shot!


All times are GMT -5. The time now is 05:04 PM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community