Starting a new thread to give you my reactions and some hard data. I don't intend to do a dyno since I didn't invest in this upgrade for performance alone and since I didn't do a dyno before I made the mod, it would be meaningless. Someone else will have to do the hard performance numbers. I jumped at GDE's offer because my interests are in all around improvement of my tractor, and that seems to be what they were concentrating on as well. Performance, Economy, Longevity. Over the last 2 years I've been driving with ORM. I used my Scanguage to clear the code on every start. The MAF got plugged in for the first time in over 2 years this week when I re-installed the ECU. I own a SEGR but never installed it.
Customer Service:
I shipped out my ECU on Wednesday June 17, returned to my doorstep on June 19th and installed same day. I hear other tuners have the same kind of door to door service. Keith from GDE was very helpful. A+
First Impressions: I've got every bit as much performance as I had with the MAF unplugged. I wish I had plugged it back in and driven it for a week before I upgraded. That would have reminded me how much of a performance boost I got when I unplugged it. For those of you still driving around stock, I think you will notice a significant performance boost. I drove about 100 miles this weekend and wanted to record my first impressions. I'll follow this up with real mpg data comparing it to data I collected last year.
Performance: No need to unplug MAF to gain performance and shut off EGR. I can't say that the EGR is shutoff completely, but It sure feels the same as with the MAF unplugged. No plans in the near future to do any towing, so will report when I do.
Fuel Economy: This weekend I drove all the situations I usually do, a little highway, a little residential, a little 2-lane in order to re-train the ECU, Let it get it used to my driving style. Now that I've done that, I'm filling the tank and getting ready for a mileage test using my normal driving routine.
For comparison, I'm using mileage figures from last summer ($4.00 per gallon Diesel). Essentially there were no physical differences in my CRD between July and August, just more highway miles in July. I think these figures will serve as a good comparison point.
July 2008, I drove 1147 miles and used 58.53 gallons. thats 19.595 MPG
Aug 2008, I drove 1222 miles and used 65.65 gallons. thats 18.613 MPG
I've got a couple of road trips scheduled this July so the next four weeks should be similar to last July.
Longevity: Will report as issues come up.
Oh - one more thing. I haven't installed my new TJM front bumper yet, still siting in the garage, I'll put it off until just before I head out to Ouray in Late July. Just to keep my Jeep as close to last years config as possible.
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1 July - Update
Just burned through the first full tank of fuel. Daily routine 17 miles each way to work, around town driving. Didn't notice a significant increase in MPG, gut says its a little better. One tank does not constitute a good test so once I've run 3 to 4 tanks of daily driving. i'll publish my results. II'm going to drive about 1200 miles over the next week most of it 75 mph highway and 60 mph two lane road so should have a good highway MPG by then next update.
Impressions: I Really like the way the tractor drives. Engine seems much smoother, shifts are much smoother, doesn't hunt for a gear like it used to. Rolling acceleration is great, I don't feel the turbo lag at all. Its hard to keep my foot out of it. Accleration from a standing start still has the same delay as the turbo spools up. At low speeds, I'm chirping the tires when I really get on it. So far, I'm very pleased with the tune. Someone posted that "This is the tune the Liberty should have come from the factory with" I agree whole heartedly.
Next update sometime after 12 July.
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10 July - Update
Just got back and am very pleased with the results
983 miles 43.99 gallons of fuel = 22.35 MPG.
I drove the first 90 miles in town, 330 miles on the highway at 75 mph each way, and the rest combination of two lane and in town. Normal driving habits, did a lot of passing on the two lane roads.
No matter if you use my mpg from July (18.6) or August (19.6) increase to 22.35 is greater than 10% increase in MPG makes this one of the better investments I've made to my tractor. The crazy thing is, its more fun to drive and I did this without having to go light on the skinny pedal.
Only thing I noticed this time that I haven't reported previously is a very solid shift just above 55. Didn't notice it every time, but it caught my attention at least 3 times during this trip. I like it, just didn't expect it.
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1 August - Update
Been home a week from Lake City Colorado
2816 miles on 131.15 gallons = 21.47 mpg (includes the offroad miles)
2652 miles on 111.53 gallons = 23.78 mpg (without offroad miles)
Most of this mileage is highway at 75 to 80 mph Next weekend I've got a 600 mile trip I'll try to keep under 65 all the time and see if I can improve that figure.
Had a chance to evaluate the GDE tune up around 8000-12000 feet. Performance was very good. Did see a couple of issues, but I'm not sure if they are related to GDE tune or not.
First issue - Hard starting at altitude - not a lot, but it usually kicks over very quickly. While I was in the mountains above 8000 feet, it took at least a couple of cranks, and in one instance it took a good 4 or 5 seconds for it to kick. After going to lower altitude the problem went away.
Second issue - engine temp climbed while climbing Monarch pass. It was manageable by kicking off overdrive and slowing down. Didn't see this on the way home. May have been due to the fact that I couldn't go the speed I wanted to on the way west as I was following a long line of vehicles. On the way home I wasn't following anyone and picked the speed that felt right.
Very happy with the performance of my tractor with the GDE tune
