Why does my mpg get worse as time passes ...

miamitj · **Posted:** Tue Dec 12, 2006 1:57 am

I originally got the CRD because I am a BIG jeep fan and a buddy was having great luck with his. He was also getting 32MPG. When I got mine it did about 22MPG and I figured it would get better as his did. I now have 7K miles and its now down to about 19mpg. Its going the wrong way. Any ideas?

Special Agent · **Posted:** Tue Dec 12, 2006 2:59 am

I've never gotten better than 21 per tank... But then again, I run B20 (20% biodiesel).

The mechanic at the dealership told me I needed to tow something heavy and speed up a few hills to really get the engine broken in...

But yeah, my average is 19mpg. I dunno how all these people get mid to high 20s...

onthehunt · **Posted:** Tue Dec 12, 2006 3:11 am

If I get on an interstate and drive for 400 miles straight at 72mph I will get 28-30 mpg. Anything else it's 19-24 mpg depending on how much stop and go is included. City driving really kills my mpg average.

Me&MyCRD · **Posted:** Tue Dec 12, 2006 7:27 am

I have 6,100 miles on my CRD and the best I have ever gotten was 30 mpg on a trip to Ocean City MD. Most of it was highway driving. Normal driving I get about 20-25 at best.

Eric

RTStabler51 · **Posted:** Tue Dec 12, 2006 9:29 am

Remember the winter fuels are out and have dropped the MPG. In DC stop and go traffic I usually get ~22mpg. Now with the winterized fuel, I'm down to about 19mpg, and I have 24.3k on the clock. I believe my engine is broken in as I've towed 5k lbs+ 3 times over about 2500 miles, so she's been worked.

Jeger · **Posted:** Tue Dec 12, 2006 9:37 am

Do they get winterized fuel in Miami? If they do it is only because the refinery or whoever mixes the fuel doesnt want to mix theirs different.

richardkf · **Joined:** Wed Jun 14, 2006 4:15 pm **Posts:** 167

constant hard accelearation, frequent stop and go trafic, using the four wheel drive, longer winter warm up idle times on cold mornings, winter blends of diesel, towing trailers ... all of these tihngs effect overall mpg per trip and per tank, depending on climate and load.

The advertised 26 mpg by Chrysler and the 28 to 30 mpg a lot of people achieve are when conditions are ideal --> Two wheel drive, frequent 65 to 72 mph long stretches of highway drives.

My CRD has not achieved the upper 20's in gas milage since I took it on a 400 all highway mile trip - and I had to drive it gently to get the milage up that high.

In regular mixed highway/city driving, without full time or 4WD, and normal acceleration 18 to 23 mpg is the norm.

rs4mtnitro · **Posted:** Tue Dec 12, 2006 9:40 am

I averaged 20 mpg till I went to the sand dunes for a couple of days and ran it hard now I average 24. Well in the summer, now its dropped off some.

DarbyWalters · **Posted:** Tue Dec 12, 2006 10:04 am

Winterized Fuel AND ULSD is reported to affect mileage 4-5%. I have had readings of 33mpg on a few tanks under ideal conditions but you have to remember that one tank is not that accurate of a reading. Now that my engine has been replaced (at 8100 miles) my mileage is down a bit. Probably a few things responsible for that...breakin, winter fuel and ULSD.

otty · **Joined:** Sun Jul 24, 2005 8:28 pm **Posts:** 22

I have had my EGR replaced twice in 20,000 miles. Each time leading up to the EGR failure my fuel mileage dropped. Other symptoms: Black smoke upon acceleration (most noticeable at night when accelerating away from cars behind you - it is very evident in the lights of the cars), hesitation when accelerating.

kb61751 · **Posted:** Tue Dec 12, 2006 1:32 pm

DarbyWalters wrote:

Winterized Fuel AND ULSD is reported to affect mileage 4-5%. I have had readings of 33mpg on a few tanks under ideal conditions but you have to remember that one tank is not that accurate of a reading. Now that my engine has been replaced (at 8100 miles) my mileage is down a bit. Probably a few things responsible for that...breakin, winter fuel and ULSD.

Why did you have the engine replaced? what went wrong?

DZL_LOU · **Posted:** Tue Dec 12, 2006 1:40 pm

[quote="richardkf"]
My CRD has not achieved the upper 20's in gas milage since I took it on a 400 all highway mile trip - and I had to drive it gently to get the milage up that high.
[\quote]

GAS? Surely not in your CRD!

runningbird · **Posted:** Tue Dec 12, 2006 1:57 pm

ours got better after my wife towed a two horse trailer with one horse, prob. 4500 lbs. up to the mountains. she said the temp got on the hot side on steep hills, and she did not know to take it out of OD. since then h/w has been 28-30.5 and in town 24-26 and she does not drive nice. I do much better in town. close to 28.

KenJennings · **Posted:** Tue Dec 12, 2006 2:58 pm

richardkf wrote:

... The advertised 26 mpg by Chrysler and the 28 to 30 mpg a lot of people achieve are when conditions are ideal --> Two wheel drive, frequent 65 to 72 mph long stretches of highway drives ....

My understanding is that the EPA tests are run the same for all vehicles and the tests are geared toward gas engines, so it is less than ideal for diesel and makes the diesel test results artificially low. A number of people report much higher mileage than the EPA tests, because they drive with consideration for the engine.

My wife drives without thinking about anything. Accelerate, Brake, Accelerate, Brake. On the few occasions I let her drive the CRD for any length of time the EVIC fell to 18mpg. (And she earns herself even lower mileage in her 4cyl Saturn Vue, too.) I'm a little less hysterical when I drive and the EVIC runs from 25 to 26 mpg for my daily, routine driving to/from work.

When the CRD was new it averaged 22mpg. And then a few months later the average fell and no matter how nice I was to the CRD it stayed near 20mpg until 10,000 miles. At 10,0000 miles it was like someone flipped a switch and the average mpg shot up. The last two tanks have been mid to high 23s for the daily, routine driving. Looking at the mileage on the current tank (and taking into account gravity, wind, and curvature of the earth ;-)

) it looks like this tank will end up averaging over 24mpg.

richardkf · **Joined:** Wed Jun 14, 2006 4:15 pm **Posts:** 167

DZL_LOU wrote:

richardkf wrote:

My CRD has not achieved the upper 20's in gas milage since I took it on a 400 all highway mile trip - and I had to drive it gently to get the milage up that high.
[\quote]

GAS? Surely not in your CRD!

ha ha ha ha ha ... it's my first diesel. I still say that, "I have to get gas" when I am going to fill up the CRD. Plus, my other vehichle has a gas engine. Old habits die hard! :shock:

DarbyWalters · **Posted:** Tue Dec 12, 2006 3:12 pm

kb61751 wrote:

Why did you have the engine replaced? what went wrong?

A valve keeper let go and the valve dropped into cylinder 1, lodged in the piston then tapped danced the head and glow plug. DC was very good about a rental car (extended warranty benefit of 5 days plus the extra dats no problem ) and complete replacement with new engine.

Bovie · **Posted:** Thu Dec 14, 2006 1:32 am

I don't get it either. When I bought it I was getting 20-22mpg with a high of 27mpg. Now at 6800miles it's under 20mpg no matter what I do for my daily commute. I'm hopinng when I hit 10k it will gow back up again like most people have said. Since day one I've spent $976.51 on fuel at a average of 19.8mpg over the 6800 miles.

Desert_Busa · **Posted:** Thu Dec 14, 2006 3:03 am

32 psi (dealer special)
19 mpgs city
29 mpgs highway pulling small 4x8 trailer to Glamis and back dirt bike on it
ride: plush and out of control wavy feeling
tire wear: How are your tires wearing?

42 psi (max cold 45 psi on the sidewall)
23 mpgs city
32 mpgs highway pulling a small 4x8 trailer to New Mexico and back light load ~300lbs
ride: firmer but not quite 22" wheel like, but its a 4x4... it would be a disgrace.
tire wear: even, but are starting to look out of round (college job: DTC tire inspector 2 years with 50k+ tires inspected)

11.4k miles ltd crd have pulled a ~3500# trailer in 117 degree heat, which may have broke it in a little

Joe Romas · **Posted:** Thu Dec 14, 2006 8:33 am

kb61751 wrote:

DarbyWalters wrote:

Winterized Fuel AND ULSD is reported to affect mileage 4-5%. I have had readings of 33mpg on a few tanks under ideal conditions but you have to remember that one tank is not that accurate of a reading. Now that my engine has been replaced (at 8100 miles) my mileage is down a bit. Probably a few things responsible for that...breakin, winter fuel and ULSD.

Why did you have the engine replaced? what went wrong?

It dropped a valve and trashed his engine :roll:

Joe Romas · **Posted:** Thu Dec 14, 2006 8:42 am

My 06 with 4k miles is also is in the 18-20 range with all short trip rarely getts totally warmed up driving. But that's twice what my 99 Cherokee got so that's a big improvement

My experience with VW diesels is that it can take as much as 20k miles to loosen up enough to get really good mileage. So hook it up to something big and charge down the interstate as others have suggested or just wait :wink:

You may also want to check your air cleaner as RFDCRD has suggested.

Why does my mpg get worse as time passes ...

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