2.8L Liberty MPG

lanthony2020 · **Joined:** Sun Feb 09, 2014 11:52 am **Posts:** 27

I recently posted my MPG on two sites. Thought I would see what folks are getting.

GDE Eco/Full-Torque, KN, GDE TCM Tow

Page, AZ to Flagstaff, AZ keeping it at 68mpg as much as possible, just over 32.5 MPG.

Took off Roof rack and removed rusted cat and muffler:

Page, AZ to St. George, Utah trip. Wanted to check mileage once more. Wind started to blow and was quite challenging both ways.

Took off bike rack. Had cat/muffler removed as it almost fell off. Muffler guy fabricated and install 2.5" pipe (only) through original route. Nice howl and rumble. At about 2500, she takes off like a raped ape for about 700 rmp. The flow must improve in about this range, I suspect?

Mileage: Very hilly with variable elevations. Small towns and a big run of lights through Hurricane, UT. Total round trip was 306 miles including some city driving in St. George. Filled up at same fuel station, same spot.

Result: 28.6 MPG trying to maintain 68 MPH. I have Toyo Open Country tires. I might be 1-2 MPH off on speedo. Might be tires. Speed trap had me off by two and GDE shift point, off my one. Have not tried to quantify the effect of this until I research further.

LN

Army Ranger · **Posted:** Mon Mar 17, 2014 9:25 pm

Are your MPG numbers off of the display above the rear-view mirror (EVIC) or are they hand calculated using the odometer?
Have you double checked your odometer's accuracy against GPS and/or road side mile markers over a considerable distance?

Hexus · **Posted:** Tue Mar 18, 2014 2:18 am

30-34 depending on drive distance, average speed, and terrain.

Hand calculated, verified per gallons filled up over 6 month average, with moderate driving (read: little turbo).

thermorex · **Posted:** Tue Mar 18, 2014 7:21 am

Best I got was 30 and some change, 500 miles roughly, cruising at 71mph, with electric fan that replaced the viscous. Previously best was 28 (with viscous). City drive summer about 25. No EVIC.

lanthony2020 · **Joined:** Sun Feb 09, 2014 11:52 am **Posts:** 27

I am checking MPG using the Odometer and calculator at the pump. I would like to know more about the fan replacement. Why not, if it helps.

I have a built in GPS units in my other two vehicles. This came with a new BT Kenwood non-gps stock replacement. Real nice but no GPS and single DIN.

Had a pioneer single din in my old Duramax. Problems with the robotics all the time and 2k to boot. I think I can use an old Garmin I have some where. I also have checked using mile markers and GPS years past. Thanks for the reminder. I will test and post.

LN

lanthony2020 · **Joined:** Sun Feb 09, 2014 11:52 am **Posts:** 27

Got GPS out and checked my Liberty for accuracy. Very close at all observed speeds. The GPS floats a bit by several tenths. It floated a little low but always hit the odometer target or match and bounced just over but mostly under by a bit more. I would say it is .2 - .3 tenth of MPH under at 68 mph. My tires can account for this much. I also overran the mile marker about 30 feet to make a mile on my trip meter.

Findings: I think I am getting very close to my reported MPG. This was great news for me. I will continue to post after trips including a new trip to Flagstaff, AZ with the new mods.

If you are not getting these numbers and have the GDE mods, I would check, clean and/or replace your MAP sensor. If it is coated or caked up it will will really screw up your air/fuel mixture.

LN

GDE Eco-torque, GDE TCM - Tow/Mountain, no cat - no muff, KN filter.

dennhop · **Posted:** Fri Mar 21, 2014 11:03 pm

12 mpg in town... I haven't figure don't what's wrong yet.

CATCRD · **Posted:** Sat Mar 22, 2014 12:53 am

20 city, 27 highway. Not going to get into best-ever numbers. Very cold weather and winter fuel will bring it down to 18 city. Lifetime average is 24, all hand calculated, corrected for odometer error.

Flying J · **Posted:** Sun Mar 23, 2014 11:29 pm

I've got the last 55k miles in a spreadsheet. 95% of the driving is around town/lots of stop and go. And we do have winter blend diesel from October to March 1. Parks in a garage so winter warm-up time is pretty reasonable, and it doesn't get THAT cold here.

Pre GDE was 20.72 total average (37k miles)
Post GDE was 24.53 total average (18k miles)

All hand-calc'd using the odometer. The highway only trips are in the 27-29 range w/ GDE. Odo been checked with a GPS.

Completely stock otherwise. I clean the map sensor about every 5-7k (although since GDE it stays clean.) Toyo AT tires.

I should put the earlier fill-ups in the spreadsheet some winter night. I have every fuel receipt since I drove it off the lot brand new in May 2005 (my wife says its a sickness)

mass-hole · **Posted:** Mon Mar 24, 2014 9:56 am

lanthony2020 wrote:

Got GPS out and checked my Liberty for accuracy. Very close at all observed speeds. The GPS floats a bit by several tenths. It floated a little low but always hit the odometer target or match and bounced just over but mostly under by a bit more. I would say it is .2 - .3 tenth of MPH under at 68 mph. My tires can account for this much. I also overran the mile marker about 30 feet to make a mile on my trip meter.

Findings: I think I am getting very close to my reported MPG. This was great news for me. I will continue to post after trips including a new trip to Flagstaff, AZ with the new mods.

If you are not getting these numbers and have the GDE mods, I would check, clean and/or replace your MAP sensor. If it is coated or caked up it will will really screw up your air/fuel mixture.

LN

GDE Eco-torque, GDE TCM - Tow/Mountain, no cat - no muff, KN filter.

My odometer is about 5% slow and my speedometer is about 5% fast. I am almost positive that the EVIC's uses the Speedometer values to differentiate the gas mileage because my evics reads about 5% high.

blackfin2 · **Posted:** Mon Mar 24, 2014 10:54 am

I live farther South than most of you, which means it's usually always warm, about like the southern half of Florida. With that said, I have the GDE tune, and my CRD gets 22-24 mpg average around town style driving. When I drive long distance and keep it at or near 70mph, it will get 28-30mpg. Once it calculated out to 31mpg. This is from sea level to a couple hundred feet higher. Before the GDE it would average 25-27mpg on the same long distance trip. In town before the GDE it has averaged 20-22 mpg. Calculated on a per tank basis. Plus, I think the fuel pumps(station pumps) this far south are calibrated at 80 degrees fuel temp per gallon volume.

I haven't taken my CRD much above sea level since installing the tune. But, before the tune when I would drive it in altitudes ranging from 1500-4000 feet it would post about a 2 mpg better average than at sea level. I'm not sure if this is caused by the altitude or a different volume of fuel measured on gas station pumps farther north.

Plus, the few times that I have had it on I-10 between Fort Stockton and San Antonio, driving at and over the posted 80mph speed limit, it averaged 25-26 mpg (pre GDE)

immadmacs · **Posted:** Wed Mar 26, 2014 2:25 pm

I've been getting an average of 17-19 mpg for the life of the vehicle. Once, and only once, I got 25mpg. I do have Firestone Destination AT tires and a roof rack, but I get nowhere near the mileage y'all are getting.

flman · **Posted:** Wed Mar 26, 2014 6:37 pm

24 to 30 MPG for me, I have the OE style Wranglers on the work horse, and Michelin with a passenger type tread on the other, and no extra wind drag.

crdjoe · **Posted:** Thu Apr 03, 2014 9:36 pm

Have the GDE eco and trans tune also the 2008 D3500 torque converter it locks up at about 56 mph so driving from Marquette, Michigan to St. Ignes ( Mackinaw bridge ) it was a warm 50 in Nov. I got 35 mpg going 61 mph using the cruise that's with P245/75/16 Michelin LTX AT2 39 psi frt. and 35 rr. as it gets colder it falls a lot. In the winter if the temp is below 45 I block 5 of the 7 grille openings and remove the fresh air feed to the air box and duct tape the opening the tube goes to. In California in the sierras mtns. It was last week of Aug. 2013 and I averaged 26 to 30 mpg and passed everyone on the hills ( Love the torque ) The speed limit was 65 so that's about optimum........if it only fixed itself it would be a perfect relationship!......LOL :JEEPIN:

2.8L Liberty MPG

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