Oddly low MPG

mngoat01 · **Joined:** Wed Aug 06, 2008 11:25 am **Posts:** 67

I have an 05 and my temp gauge sat exactly where yours is at now. Was getting a little over 15 mph here in the Minnesota winter.(mostly city driving, have short trip to work) Changed out thermostat 3 weeks ago and it jumped to 18.5 almost 19 at times. Hand calculated. Same fuel station and the temps have not change at all. Just as cold. Heat got better in the cab also. Hope this helps.

dgeist · **Posted:** Thu Feb 03, 2011 5:42 pm

irollgen4s wrote:

Im not trying to disprove you in anyway, im just saying with or without the correction, my mileage is still extremely off for what how im driving. I think im going to wait until its slightly warmer and then look into the thermostat more, mainly because my dad doesnt want to bother with it now

Thanks everyone!

In the mean time, you can pile on the winter jackets and run the AC on max inside the cab to help put load on the engine. Ever since my t-stat started to go, I get BETTER fuel economy with the AC on

dieseldoesit · **Posted:** Thu Feb 03, 2011 6:29 pm

crap, mine is bad too... now if only the dang tranny will start to shudder... got 1k left to go on the warranty...

benzer · **Posted:** Thu Feb 03, 2011 8:06 pm

This morning it was -11 air temp. My temp gauge was
halfway between 1/4 and 1/2, it would not climb higher
until I turned the climate control fan down from 3 to 2.

My thermostat is less than a month old, but I do not
have anything blocking the grill either.

My EVIC has been at 19-21 MPG for this tank. I have just
under 1/2, so I have not hand calculated yet.........

Just chiming in.........

John

irollgen4s · **Posted:** Thu Feb 03, 2011 10:10 pm

Thanks to you guys im sure its the thermostat, I keep my heat on 1 at all times unless its a very frigid morning, for warming up i usually start it for five minutes before i leave to let the oil circulate, then in maybe 2-3 of 55mph its warmed up and shifts into the top gears. The heat doesnt seem any colder then before, but i also wasn't looking for it.

My main concern is the MASSIVE hit to the MPG. Im going to run another tank through it and make sure it is still ridiculously low, then depending on the results im going to replace the tstat. Thanks everyone! i hope this topic helped others too.

greggmig · **Posted:** Tue Feb 08, 2011 11:17 am

Is a thermostat covered under the 7 -70,000 mile warranty? :?:

Joe Romas · **Posted:** Wed Feb 09, 2011 8:43 am

greggmig wrote:

Is a thermistat covered under the 7 -70,000 mile warranty? :?:

You don't have your year in your signature so we don't know what warranty your talking about. The 05 factory warranty had a power train 7/70 but the 06 was only 36/3

I have a 06 with with the Chrysler Gold extended warranty for 7/70 and it would have covered the thermostat, $100 deductable, but flushing the system would be on my nickel :juggle:

Joe Romas · **Posted:** Wed Feb 09, 2011 8:49 am

benzer wrote:

This morning it was -11 air temp. My temp gauge was
halfway between 1/4 and 1/2, it would not climb higher
until I turned the climate control fan down from 3 to 2.

My thermostat is less than a month old, but I do not
have anything blocking the grill either.
John

Diesel engines are much more effecient then gasoline ones and there is less heat produced by them. So with the heater on and -11 ambient temperatures it's not going to warm up too much. even with a new thermostat. I tried blocking the grill and it didn't much if any

Now my 4.0L Cherokee produces cabin heat by the end of the driveway but effecient it's not :SOMBRERO:

greggmig · **Posted:** Fri Feb 11, 2011 12:14 pm

Got a 2005 CRD I paid for the warranty exchange Im the scond owner. My TC is shuddering so when I bring it in for that I'll mention the thermistat. It will be a $100 deductable for both repairs I hope. :?:

Joe Romas · **Posted:** Fri Feb 11, 2011 8:22 pm

The thermostat on my 06 was good untill last summer. Then even on a 90 degree day it ran two ticks below mid point. I put a new one on last fall and it then rode 1 tick left of center that is normal. During the cold weather we're having around town it will raise to about two ticls left of center but as soon as I get on the interstate it goes to 1 tick left where it belongs.
I have the GED Eco tune and they turn the coolant heater off at a lower temperature too.
But I've never gotten 14 mpg :dizzy:

Today I filled up and got 20.51 MPG and that included a lot of full time 4x4 with slush and cold weather. But I have stock size tires and pre f37 tcm. Have you checked your air filter lately? Something is going on, Do you notice excessive brake dust on around one wheel tht would point to a brake hanging.

TJ2 · **Posted:** Fri Feb 11, 2011 9:18 pm

The FSM says that running a 3.7 gasser cold can cause it to sludge up. Is there a reason the same thing couldn't happen in a CRD?

That's worse than crappy mileage and riding around being cold.

irollgen4s · **Posted:** Sat Feb 12, 2011 12:31 am

No ridiculous brake dust and the air filter is spotless. the thermostat is being replaced soon, hopefully thats it :grim:

jmoomaw · **Posted:** Sat Feb 12, 2011 8:41 am

I didn't read all the posts so I do not know if this was suggested.

I was getting 30 mpg highway until I hit a major pot hole and damaged a tie rod. The mileage went right down to 23 mpg!!! Any pull to the left or right?

It could be all of the above, each in a small way.

My 2 cents.

Timmaah! · **Posted:** Sun Feb 13, 2011 9:45 am

irollgen4s wrote:

Hey, i have 06 CRD limited franky lifted with 265-75-16 E load general grabbers under it. I Also have a jl audio stealthbox with an amp set up that i always have going, but not always full blast. Now I just hand calculated my gas mileage, and im getting about 14 miles per gallon.... WHAT THE HELL? I have pictures of my temp gauge, and from what i've read its still fine, it's two clicks off of 90 degree's(vertical). I know I shouldnt be getting anything amazing like 26 or 28, but i feel like i should at least be in the 20's. This is with mixed driving, half town, half long 55+mph roads. Also i use four wheel drive very little, i had it on for five minutes this morning to see if it was icy, and then i use it whenever i happen to get stuck in slush or on ice while parked. I always have the heat on 1, the lowest setting and usually have it on feet and windsheild or feet and face.

The mapping is factory as well as the TCM, and i have been neutered with the f37 flash and i have the old F37 torque converter.

Help please?

Edit: also this is in winter temperatures and it sits outside all night and gets used during the day a bit. Temps range from 8 degree's at night to 40 on a good day. I have a light foot also, but have played in the snow a little bit too. I also know that gas stations put in some blend into the tanks so that it doesnt freeze or gel and i know this hurts the mieleage a bit too.

My temperature gauge is exactly where yours is when below 20F. ScanGuage indicates 155 - 157F. When it's nice weather around 75, ScanGuage reads around 167. When it's really hot out (above 100), ScanGuage reads around 180F(tops). It's been this way since new. My VW TDI runs 185 to 190F year-round, but in cold weather it takes 7 miles to get there.

papaindigo · **Posted:** Sun Feb 13, 2011 11:17 am

I cannot speak to your mpg but your tstat is failing by opening too early. It has exactly the same symptoms as mine in that at 30 degrees F or below the gauge needle road 2-2.5 ticks left of vertical, never higher; as outdoor ambient rises so does the needle until at 70 degrees F + it would read .5 tick left of vertical especially if I ran the AC. However my mpg hit was only from 23 to 21 in town but that's with the GDE Eco tune. Just a reminder that, like other diesel's I've owned, the CRD will not quickly reach operating temperature at idle or low speed, my experience is that at an average in town speed of 35 mph it takes about 2-6 miles to reach full temperature. It warms up much faster at 45-50 mph.

DOC4444 · **Posted:** Sun Feb 13, 2011 1:01 pm

Get the brakes good and hot, then immediately get it off the ground and check for excessive drag when you hand turn each wheel. KJs have a problem with both collapsing brake lines and poor piston return when hot. (If you check when everything is cold, it may appear to be fine.)

DOC

Oddly low MPG

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