Fuel Economy: Outliers

Wobbly · **Posted:** Sun Jan 17, 2010 11:47 am

Casual browsing of the forum might give the impression that your CRD's fuel economy is poorer than should be expected. Several forum posters report getting better than 30 MPG. However, the reported averages for CRDs on the FUELLY site are quite a bit lower:
http://www.fuelly.com/car/jeep/liberty/diesel%20l4

stoutdog · **Posted:** Sun Jan 17, 2010 12:02 pm

Yea, but that darn website keeps removing the "diesel L4" from my tag. I noticed that ac5501, who gets even better mileage than me, isn't on there either.

It all depends on how you drive it. And most of the CRDs on Fuelly do not have GDE Tunes.

Wobbly · **Posted:** Sun Jan 17, 2010 12:28 pm

Looking at the 2006 numbers, and throwing out those for the CRD which tows the Airstream,
the average based on number of fill ups is 20.8 MPG. (average miles/gallon * fill ups / fill ups) = 9643/463 = 20.8 MPG

linewarbr · **Posted:** Sun Jan 17, 2010 2:32 pm

Not sure how you can gather composite data on CRD Liberties from fuelly, but I have a link in my sig for my mileage. Right now mileage is poor because of winter-blend diesel and a dragging brake problem that I will fix when I finish the shutdown I'm on. I usually run between 27 and 29 depending on what kind of driving I'm doing and what type of diesel I use.

I'm sure if I had less agressive tires and drove more slowly, mine would be like stouts' mpg. . . .

DarbyWalters · **Posted:** Sun Jan 17, 2010 3:11 pm

Too many factors to draw any conclusions from all the MPG reports...driving style, route, temps, mods, ect. I think you can come to the conclusion that the CRD driven moderately will get at least 20mpg (+/-2) in all city driving...3-5 more in mixed...and over 30 mpg on the highway if rpms are kept under 2000rpm.

Wobbly · **Posted:** Sun Jan 17, 2010 3:53 pm

For the last few weeks of city driving, the EVIC has been stuck around 17.5 MPG. I coast to stop lights and accelerate gradually.

Joe Romas · **Posted:** Sun Jan 17, 2010 4:22 pm

Fuel mileage can vary greatly just from the quality the of fuel you get for a specific tank. I've owned diesel powered cars since 1978 and have noticed on several that the fuel in Georgia and Florida is much better then central ohio's crap. I once got 2 tankfulls in the 70 mpg range on a 99.5 jetta tdi. The conditions were ideal but the fuel added about 10 mpg to to those two tanks fulls. They were both on a cool damp night, windows up ac off and mostly on cruise control at 70 mph. I put 114k miles on that car and average 49.6 MPG for the total. My son has it now and can get inthe low 60's with fuel gotten close to a refinery in Toledo. I also owned a 96 Passat tdi wagon and drove 1002 miles on one tank but I don't remember the mpg figure. It was fuel bought in Georgia and my wife was saying that she was not going to walk that I was :SOMBRERO:

I filled my crd yesterday and got 20.985 mpg city all short trips with lots of 4x4 in the snow. I have 2 pieces of flexable foam about 8" thick on each side of the radiator. If a diesel does not get warm you'll not get good mileage. I got 20 on two tankfulls towing our trailer last summer. I aveaged 27.+ coming back from getting my GDE tune that seems to have added 3 to 5 mpg. I've not taken any trips without towing our trailer since the tune but suspect in warm weather I can get close to 30 mpg. this past summer my short trip intown driving averaged 24-25 mpg. I have the stock tires, Amsoil air filter, provent and an intank tank pump.

Some mention 10% odometer error and automatically add that in. I think mine is nearer to 5% off if that much :lol:

Wobbly · **Posted:** Sun Jan 17, 2010 4:45 pm

Joe Romas wrote:

... my GDE tune that seems to have added 3 to 5 mpg...

Is viscous heater control included in your tune?
BTW, our Vixen RV gets an average of 28 MPG, which is about the same as our MB 300SDL got.

vtdog · **Joined:** Fri Sep 30, 2005 11:27 am **Posts:** 640

I have owned since new and fuel economy rose through about 50k miles (engine break in for diesel?). In summer my normal combined mpg is around 25 and in winter about 22. I have gotten almost 30 on the hiway in very hot conditions driving in Michigan which does not have much of an altitude change. Winter mpg has dropped as low as 19.5, but that is with only short trips in very cold weather. My old XTERRA never got better than 17.5 ever and was often below 15 so even with the winter MPG it is hard to complain.

Joe Romas · **Posted:** Sun Jan 17, 2010 5:02 pm

Wobbly wrote:

Joe Romas wrote:

... my GDE tune that seems to have added 3 to 5 mpg...

Is viscous heater control included in your tune?
BTW, our Vixen RV gets an average of 28 MPG, which is about the same as our MB 300SDL got.

No, I was in on the one of the first 10 offer :SOMBRERO:

stoutdog · **Posted:** Sun Jan 17, 2010 8:46 pm

linewarbr wrote:

I'm sure if I had less agressive tires and drove more slowly, mine would be like stouts' mpg. . . .

How fast are you going :?:

Doing 70mph, I still get 30-31mpg.

Silverdiesel · **Posted:** Mon Jan 18, 2010 1:47 am

no GDE but with SEGR,

The worst city mileage I get is 23.5~~
Hwy 29.8 to 31--61 to 68 MPH.

And that is not figureing in the taller 215-85's which I understand adds a factor of X1.11.
Living in the desert and never having to use D1 and putting in biodiesel time and again makes a difference I believe.
:ALONE:

Roland

ac5501 · **Posted:** Mon Jan 18, 2010 8:00 am

stoutdog wrote:

Yea, but that darn website keeps removing the "diesel L4" from my tag. I noticed that ac5501, who gets even better mileage than me, isn't on there either.

It all depends on how you drive it. And most of the CRDs on Fuelly do not have GDE Tunes.

I just fixed my tag and put Diesel L4 back in. Lets see how long it lasts. As far as better mileage then you, that might be true for the summer, but since: shifting to winter diesel, new (heavier?) tires, big drop in temp, usage of the heater (turns on AC comp), lots of 4wd, my winter economy has really gone down. I have about 4000 miles of 24-26 mpg to log into fuelly. That's the reason I broke my car into summer and winter. It really is like 2 different vehicles when you compare winter and the other seasons. Don't get me wrong, I am not complaining, just pointing out.

I need to get with GDE and see if they will update my tune to include the viscous(spelling?) heater deal.

stoutdog · **Posted:** Mon Jan 18, 2010 12:19 pm

ac5501 wrote:

stoutdog wrote:

Yea, but that darn website keeps removing the "diesel L4" from my tag. I noticed that ac5501, who gets even better mileage than me, isn't on there either.

It all depends on how you drive it. And most of the CRDs on Fuelly do not have GDE Tunes.

I just fixed my tag and put Diesel L4 back in. Lets see how long it lasts. As far as better mileage then you, that might be true for the summer, but since: shifting to winter diesel, new (heavier?) tires, big drop in temp, usage of the heater (turns on AC comp), lots of 4wd, my winter economy has really gone down. I have about 4000 miles of 24-26 mpg to log into fuelly. That's the reason I broke my car into summer and winter. It really is like 2 different vehicles when you compare winter and the other seasons. Don't get me wrong, I am not complaining, just pointing out.

I need to get with GDE and see if they will update my tune to include the viscous(spelling?) heater deal.

I have the latest tune, not sure if it made much of a difference. I'm just amazed that you can get 33-34mpg (in the summer) doing 75+mph. I would totally do 75 if I got that kind of mileage... Any tips/secrets?

linewarbr · **Posted:** Mon Jan 18, 2010 12:36 pm

stoutdog wrote:

linewarbr wrote:

I'm sure if I had less agressive tires and drove more slowly, mine would be like stouts' mpg. . . .

How fast are you going :?:

Doing 70mph, I still get 30-31mpg.

I like to cruise at 83 (via GPS), which is about 86 or 87 on the uncorrected speedo. Wearing wider all-terrain tires has affected it more though. And, I find my mpg is better at 83 than at 80. Go figure.

stoutdog · **Posted:** Mon Jan 18, 2010 1:07 pm

linewarbr wrote:

stoutdog wrote:

linewarbr wrote:

I'm sure if I had less agressive tires and drove more slowly, mine would be like stouts' mpg. . . .

How fast are you going :?:

Doing 70mph, I still get 30-31mpg.

I like to cruise at 83 (via GPS), which is about 86 or 87 on the uncorrected speedo. Wearing wider all-terrain tires has affected it more though. And, I find my mpg is better at 83 than at 80. Go figure.

Ah, that would explain it. I find with these KJs that mpg drops off exponentially after 60mph...

ac5501 · **Posted:** Mon Jan 18, 2010 1:33 pm

stoutdog wrote:

ac5501 wrote:

stoutdog wrote:

Yea, but that darn website keeps removing the "diesel L4" from my tag. I noticed that ac5501, who gets even better mileage than me, isn't on there either.

It all depends on how you drive it. And most of the CRDs on Fuelly do not have GDE Tunes.

I just fixed my tag and put Diesel L4 back in. Lets see how long it lasts. As far as better mileage then you, that might be true for the summer, but since: shifting to winter diesel, new (heavier?) tires, big drop in temp, usage of the heater (turns on AC comp), lots of 4wd, my winter economy has really gone down. I have about 4000 miles of 24-26 mpg to log into fuelly. That's the reason I broke my car into summer and winter. It really is like 2 different vehicles when you compare winter and the other seasons. Don't get me wrong, I am not complaining, just pointing out.

I need to get with GDE and see if they will update my tune to include the viscous(spelling?) heater deal.

I have the latest tune, not sure if it made much of a difference. I'm just amazed that you can get 33-34mpg (in the summer) doing 75+mph. I would totally do 75 if I got that kind of mileage... Any tips/secrets?

Well, during the summer, I drive 65-70 (prob closer to 65). Sorry if I've mislead anybody. I'll have to check if i put that in my Fuelly profile.

Tips? Stay in "max overdrive" (can be difficult on 2 lane hwys) and cruise control as much as possible. Try to time lights. In short, TRY and drive it like your grandfather would. I say try because that is a really really boring way to drive. The only time I can pull it off consistantly is driving to and from work.

stoutdog · **Posted:** Mon Jan 18, 2010 3:40 pm

ac5501 wrote:

Well, during the summer, I drive 65-70 (prob closer to 65). Sorry if I've mislead anybody. I'll have to check if i put that in my Fuelly profile.

Tips? Stay in "max overdrive" (can be difficult on 2 lane hwys) and cruise control as much as possible. Try to time lights. In short, TRY and drive it like your grandfather would. I say try because that is a really really boring way to drive. The only time I can pull it off consistantly is driving to and from work.

My best tank is 35.3, and that was simply me trying to see what the CRD was capable of... I burned through an entire tank of gas driving cross country with cruise on 60, no hills, no AC, stopping only once. I do all the rest that you mentioned, when I can.

It seems, good sir, that you have a particularly fuel efficient Jeep. :POPCORN:

Fuel Economy: Outliers

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