My MPG gain is fenominal with a Pre F37 TCM

arengant · **Posted:** Thu Oct 20, 2011 10:57 pm

Quite impressive Racer! Guess it makes it worth sinking all that money fixing yours huh?

racertracer · **Posted:** Fri Oct 21, 2011 5:43 am

arengant wrote:

Quite impressive Racer! Guess it makes it worth sinking all that money fixing yours huh?

Arengant,

The most significant gain was when I replaced the TCM.

racertracer · **Posted:** Fri Oct 21, 2011 5:49 am

Joe Romas wrote:

racertracer wrote:

As far as what has been done to the engine recently (2 weeks ago), here is the list:

The ECU was reflashed by the dealer as required for the glow plug update, wiping out the GDE Hot tune. (I’ll be sending the ECU out to GDE for the reflash)
.

So this is with the latest version of the OEM tune, I wonder what you'll see when you get the GDE tune restored. You had the HOT tune, I wonder if just the full torque ECO would give better MPG's:jester:
Any idea of what PRE F37 TCM tune you have? There were at least two.

I just checked mine. The Pre F37 version I have, PER VAG-COM, is 56044737AF and that agrees with the original tag. This TCM came from a salvage yard.
My January 06 build tcm tag says 56044737AI and that was also a pre f37. I'm not sure but I think it now, post F37, is AJ per VAG-COM but it's not in the jeep so I can't check.

MY TCM is the 56044737AF

Joe Romas · **Posted:** Fri Oct 21, 2011 5:41 pm

racertracer wrote:

MY TCM is the 56044737AF

So we both have the same TCM firmware flash. The only down side if you can call it that for me is the delay when at 59 mph and it first unlocks the tc in 4th then shifts to fifth and then locks the tc back up :?:

I had my F37 tcm in for a trip we took with the camper last month, it's more suited for towing our trailer, and just in the past week put the AF version back in and had forgotten how long the unlock the tc in 4th, shift to 5th then lock the tc back up seems to take. The f37 version the 4 to 5 shift is barley detectable.
I wonder what the AI version is like that mine originally came with :?:

racertracer · **Posted:** Sat Oct 22, 2011 6:30 am

Went on a 471.4 miles round-trip yesterday and here are the results.

To correctly measure how much fuel was used, I hand calculated the results.

Before departing I filled the tank to the top of the filler tube until it couldn't take anymore.

Upon return, I again filled the tank to the top of the filler tube until it couldn't take anymore and recorded the amount of fuel used.

Total fuel used was 15.134 Gallons = 31.15 MPG

The EVIC was showing 35.6 MPG at one time, it fluctuated during the trip at different speeds, especially when just once I couldn't keep myself from blowing smoke in the nose of a menacing Hummer bullying me to let him pass, that brought the MPG down a bit.

Traveling speed varied - Mostly 63 to 75 MPH. I discovered that maintaining the RPM between 1700 to 1950 produced the best results.

75mph = 1950rpm.
63mph = 1700rpm

I didn't realize my tires were low during the first leg of the trip and I might have gotten better mileage if they were filled because after filling them the MPG on the EVIC increased even more.

The MAF sensor is still disconnected and the CEL light on the dash remains off, maybe part of the new glow plug ECU software update, who knows.

Never in the life of this vehicle has the EVIC ever gone passed 27 MPG, the engine has never sounded this smooth and performed so well. I am extremely happy with the work that was done, especially installing the pre F37 TCM.

We should be aware that we have an incredible vehicle capable of being super efficient if maintained correctly.

Racer

ATXKJ · **Posted:** Sat Oct 22, 2011 8:44 am

Well - the true difference F37 pre/post and GDE tranny tunes is in town shifting through the gears - it will be interesting to see how it performs there.

would also be interested in knowing if the engine revs to ~ 1000 rpm on startup for a fraction of a second.

Joe Romas · **Posted:** Sat Oct 22, 2011 9:17 am

ATXKJ wrote:

Well - the true difference F37 pre/post and GDE tranny tunes is in town shifting through the gears - it will be interesting to see how it performs there.

would also be interested in knowing if the engine revs to ~ 1000 rpm on startup for a fraction of a second.

My Pre F37 TCM shifts 5 mph sooner in all gears as far as I can tell and I get 2 to 4 mpg better with it.

The 1000 rpm on startup is from the GDE ECM tunes :wink:

I have GDE's "Full Torque Eco" ECM tune and both of my STOCK pre and Post F37 TCMs (not gde's tcm tune) and the 1000 start up burst happens with both tcm's

That is if your not implying that Chrysler may have incorporated some of GDE's features on their latest flash :wink:

It would be nice to know what other changes were incorporated if any besides for the 5 volt gp's :?:

racertracer · **Posted:** Sat Oct 22, 2011 9:57 am

At start up my tach does reach just under the 1000 rpm for a second and then drops down.
What does this mean?

ATXKJ · **Posted:** Sat Oct 22, 2011 10:08 am

racertracer wrote:

At start up my tach does reach just under the 1000 rpm for a second and then drops down.
What does this mean?

that's a GDE signature - the stock tune's don't do that.
It means the Glow Plug flash did not overwrite the entire GDE tune -only the Glow plug voltage.

it also explains why the CEL isn't coming on.

Joe - I doublechecked my records F37 dropped my mileage 0.3 mpg - in town - no change at all on the highway. Eco tune added +2.1 mpg in town (6 tank avg before/after)

Joe Romas · **Posted:** Sat Oct 22, 2011 10:40 am

ATXKJ wrote:

racertracer wrote:

Joe - I doublechecked my records F37 dropped my mileage 0.3 mpg - in town - no change at all on the highway. Eco tune added +2.1 mpg in town (6 tank avg before/after)

I don't have any figures on my pre f37 flash. Mine had a coolant leak in June of 06 when 2 weeks old before I had used a full tank and they flashed it with the pre f37 flash that that made the same changes as f37 but also caused them to not communicate with with third party scanners resulting in the F31 recall some of us got. When they did the f31 I got the real or final F37 and there were no noticable differences from what I had previously gotten and the final f37.

My in town numbers went up 2 mpg with the eco tune and another 2 with the pre f37 tcm for a summer, warm weather, of a solid 24 mpg. My only highway figures are towing our trailer and the F37 tune works better towing for me. Towing our camping trailer, a 17' Casita that's about 3500#, through VA , WV, NC, GA and Fla on a 2500 mile trip my averages per tank were 17 to 20.009 MPG or about 19 mpg total :jester:

That makes for a happy camper and I'm not a slow poke on Interstates :goink:

ATXKJ · **Posted:** Sat Oct 22, 2011 11:23 am

I don't tow - but I ran a year and a half pre F37 -
and I almost gave it back to them after they did that - killed the performance - over -reved the torque peak - however it stayed locked better - so depending on your normal drive it could make mileage better or worse.

However - brand new totally stock I drove up to Colorado and had several tanks in the 25.5-26 range - so I don't doubt that adding the ORM and a broken in engine you could get 30 - steady state ~65mph

However I don't know of a non electronic way to get rid of the CEL when you do that.

Joe Romas · **Posted:** Sat Oct 22, 2011 2:33 pm

ATXKJ wrote:

so I don't doubt that adding the ORM and a broken in engine you could get 30 - steady state ~65mph

However I don't know of a non electronic way to get rid of the CEL when you do that.

contact GDE :BINGO:

yrkcrd · **Posted:** Sat Oct 22, 2011 8:09 pm

racertracer wrote:

Joe Romas wrote:

racertracer wrote:

As far as what has been done to the engine recently (2 weeks ago), here is the list:

The ECU was reflashed by the dealer as required for the glow plug update, wiping out the GDE Hot tune. (I’ll be sending the ECU out to GDE for the reflash)
.

So this is with the latest version of the OEM tune, I wonder what you'll see when you get the GDE tune restored. You had the HOT tune, I wonder if just the full torque ECO would give better MPG's:jester:
Any idea of what PRE F37 TCM tune you have? There were at least two.

I just checked mine. The Pre F37 version I have, PER VAG-COM, is 56044737AF and that agrees with the original tag. This TCM came from a salvage yard.
My January 06 build tcm tag says 56044737AI and that was also a pre f37. I'm not sure but I think it now, post F37, is AJ per VAG-COM but it's not in the jeep so I can't check.

MY TCM is the 56044737AF

Hmm same as my TCM! Cool does that mean I have pre-F37?? :pepper:

xtriggerman · **Posted:** Sat Oct 22, 2011 10:51 pm

We just bought a absolutely cherry 05 w/ 64K on it and find this a interesting post. The secondary roads we drive for the most part put us in the 45-55mph range. The trany must be F37 since 60-61mph is the only way to hit 5th. If the pre F37 makes use of 5th in the 55mph speed, how can I get my TCM tuned back to a pre F37 tune? The noob guide claimed there is such a service but didnt mention where to go for it. For an interesting shutter/jutter story see my new post on it.

arengant · **Posted:** Sat Oct 22, 2011 10:58 pm

xtriggerman wrote:

We just bought a absolutely cherry 05 w/ 64K on it and find this a interesting post. The secondary roads we drive for the most part put us in the 45-55mph range. The trany must be F37 since 60-61mph is the only way to hit 5th. If the pre F37 makes use of 5th in the 55mph speed, how can I get my TCM tuned back to a pre F37 tune? The noob guide claimed there is such a service but didnt mention where to go for it. For an interesting shutter/jutter story see my new post on it.

Buy the TCM tune from GDE http://www.greendieselengineering.com/goPage.do?method=home AFTER you put in a Euro TC

xtriggerman · **Posted:** Sun Oct 23, 2011 12:46 am

arengant wrote:

xtriggerman wrote:

We just bought a absolutely cherry 05 w/ 64K on it and find this a interesting post. The secondary roads we drive for the most part put us in the 45-55mph range. The trany must be F37 since 60-61mph is the only way to hit 5th. If the pre F37 makes use of 5th in the 55mph speed, how can I get my TCM tuned back to a pre F37 tune? The noob guide claimed there is such a service but didnt mention where to go for it. For an interesting shutter/jutter story see my new post on it.

Buy the TCM tune from GDE http://www.greendieselengineering.com/goPage.do?method=home AFTER you put in a Euro TC

The GDE ECO tune says nothing about shift points used by the TCM. Im interested in the lower shift points of pre F-37 as a first step (after a 3 Amsoil trans oil change). Maybe ECM tune latter..

racertracer · **Posted:** Sun Oct 23, 2011 1:30 am

I don't know if it had any effect on the MPG, but I failed to mention that I poured a bottle of ZMAX in the oil when I got the car back home after all the work was done.

arengant · **Posted:** Sun Oct 23, 2011 1:34 am

Here it talks about TC lock up, kinda like a half shift

http://www.greendieselengineering.com/f ... st/89.page

Holds 5th down to 52, mine right now is about 57

Joe Romas · **Posted:** Sun Oct 23, 2011 7:48 am

xtriggerman wrote:

Buy the TCM tune from GDE http://www.greendieselengineering.com/goPage.do?method=home AFTER you put in a Euro TC

The GDE ECO tune says nothing about shift points used by the TCM. Im interested in the lower shift points of pre F-37 as a first step (after a 3 Amsoil trans oil change). Maybe ECM tune latter..[/quote]

That's because we're talking about the GDE TCM tune :ROTFL:

xtriggerman · **Posted:** Sun Oct 23, 2011 11:41 am

Joe Romas wrote:

xtriggerman wrote:

Buy the TCM tune from GDE http://www.greendieselengineering.com/goPage.do?method=home AFTER you put in a Euro TC

The GDE ECO tune says nothing about shift points used by the TCM. Im interested in the lower shift points of pre F-37 as a first step (after a 3 Amsoil trans oil change). Maybe ECM tune latter..

That's because we're talking about the GDE TCM tune :ROTFL:

[/quote]

The link provided has no mention what so ever of a TCM tune.... :goink:

arengant, THANKS for this link http://www.greendieselengineering.com/f ... st/89.page its exactly what I wanted to know. :BINGO:

My MPG gain is fenominal with a Pre F37 TCM

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