GDE fuel economy

LibertyCRD · **Posted:** Tue Feb 09, 2010 4:18 pm

I'm at the half tank mark. 175 miles driven (conservatively driven too). :cry:

That would work out to 18 MPG assuming the guage is now truly linear. Boo hiss.

linewarbr · **Posted:** Tue Feb 09, 2010 4:25 pm

Make sure you figure for speedometer/ odometer error. That's why I picked up a Garmin.

dgeist · **Posted:** Tue Feb 09, 2010 4:49 pm

Also, with 255/70's it't probably off, anyway. GDE isn't a miracle cure that makes you hit a specific number, but you should see an improvement over what it was before. What were you seeing before?

Have you already done the normal things that rob fuel economy (like cleaning the crust off the MAP sensor in the manifold)?

Dan

flman · **Posted:** Tue Feb 09, 2010 4:50 pm

Cant figure it that way, the only way to be accurate is a refill.

LibertyCRD · **Posted:** Tue Feb 09, 2010 5:22 pm

I cleaned my MAP sensor. I GPS verified that my speedometer is perfectly accurate. I was hand calculating AND using EVIC pre-GDE and was getting 19.5-21.0 MPG. My EVIC was perfectly accurate by the way. So far, post-GDE the EVIC says 23.0 MPG but judging by the miles driven/fuel used I'm actually around 18 or 19 MPG.

I will say though, I'm running Power Service anti-gel and injector cleaner, so that may be hurting.

Goglio704 · **Posted:** Tue Feb 09, 2010 6:06 pm

I know on my CRD the Speedometer was dead on, but the Odometer was about 2% low if I remember correctly.

CRD Joe · **Posted:** Tue Feb 09, 2010 6:34 pm

darn that doesnt make sense. Ive got an Inmotion stage two and I regularly get 550 to 600 per tank.

LibertyCRD · **Posted:** Tue Feb 09, 2010 6:46 pm

Right now I'm doing 350-400 miles per tank driving like an old man. Its rather pathetic. I'm going to have to try some different diesel or something.

flman · **Posted:** Tue Feb 09, 2010 7:10 pm

LibertyCRD wrote:

Right now I'm doing 350-400 miles per tank driving like an old man. Its rather pathetic. I'm going to have to try some different diesel or something.

Oil is oil, that is all diesel really is. Any ways, are the brakes sticking, air cleaner Ok, front end alignment OK, running in 2wd or 4wd? Could be a lot of things, but all our Jeeps have the same ECU program whether it be stock or tuned, to lay this problem on the GDE tune is a far fetch. Maybe some one else will jump in with an idea?

warp2diesel · **Posted:** Tue Feb 09, 2010 9:34 pm

LibertyCRD wrote:

Right now I'm doing 350-400 miles per tank driving like an old man. Its rather pathetic. I'm going to have to try some different diesel or something.

Running Citgo :?:

No chip tuner can fix that crap :!:

Bad foaming too :!:

Worst #2 Diesel I ever bought, mileage sucked and power sucked big time :!:

Also check your odometer, I have to multiply my reading by 1.115 to correct (tire size in signature).

LibertyCRD · **Posted:** Tue Feb 09, 2010 10:25 pm

I'm not blaming anything on GDE. I'm basically just saying that my mileage has not increased at all, despite driving more conservatively than before. Everything is in perfect shape on this Jeep from what I can tell. If the brakes are sticking or if the odometer is off then it would have been that way pre-tune also. I was expecting an improvement in MPG and early on it appears I'm not going to get it. Will check back again after I hand calculate some tanks.

flman · **Posted:** Tue Feb 09, 2010 10:41 pm

LibertyCRD wrote:

I'm not blaming anything on GDE. I'm basically just saying that my mileage has not increased at all, despite driving more conservatively than before. Everything is in perfect shape on this Jeep from what I can tell. If the brakes are sticking or if the odometer is off then it would have been that way pre-tune also. I was expecting an improvement in MPG and early on it appears I'm not going to get it. Will check back again after I hand calculate some tanks.

Sorry, the title of your thread implied :juggle:

Any ways, are you running Citgo? I have run it before with no adverse affects. I am almost thinking at the oil company down the road from me they sell Citgo, and I run it almost exclusively out of convenience. I notice it did foam up in the saddle tank of my truck, but I have seen the same thing at Hess.

That is too bad, you did not get the results you wanted. Maybe you should run a few tanks, and get an average going? Wish you luck, and good results.

geordi · **Posted:** Tue Feb 09, 2010 10:44 pm

I've been stuck in the 350-400 miles-per-tank club for months... What is the other sensor on the airbox? What does that do for economy exactly?

linewarbr · **Posted:** Tue Feb 09, 2010 11:23 pm

That other sensor - the one with the Mercedes insignia on it - is the intake air temperature sensor.

thunderbear · **Posted:** Wed Feb 10, 2010 12:35 am

I'd kill for 300+ miles per tank in my TJ :lol:

WolverineFW · **Posted:** Wed Feb 10, 2010 1:08 am

Didn't you just get new All-Terrain tires?

stoutdog · **Posted:** Wed Feb 10, 2010 1:32 am

I'd wait until you actually fill up to worry about your fuel economy... The linear fuel gauge takes a little bit of getting used to. I still wouldn't trust it whole-heartedly.

If you see zero mpg improvement, contact GDE. You should gain at least 10%. The worst I have ever gotten on a tank after my tune was around 26mpg, and that was mostly in town driving.

baddabing · **Posted:** Wed Feb 10, 2010 1:47 am

I don't have a GDE, just an SEGR. My Libby has always hit 350 miles per tank, combined highway / city with (245/70/16)tires. I always thought it should do better than that. Once I hit 400 miles once with a lot of freeway driving. I clean the map sensor every oil change and change the fuel filter every second oil change. Driving characteristics are about Joe average. Is 350 miles about right? Should I try run a fuel injector cleaner throught it?

Any thoughts?

CRD Joe · **Posted:** Wed Feb 10, 2010 5:12 am

When I bought my truck it had the original Goodyears on it and they were BALD! I drove at 57mph from Nashville to Seattle and I averaged 36+ MPG! One tank was barely 38. I had my mirrors folded in and I took my antenna off. XM baby.

flman · **Posted:** Wed Feb 10, 2010 6:32 am

I agree, new AT tires could be the culprit. Pump all 4 or them up to at least 35 PSI.

GDE fuel economy

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