Gas Milage ...

Ricky5 · **Posted:** Thu Oct 20, 2005 12:34 pm

Was wondering ... I have been through three tanks of gas on my CRD since I bought it brand new. Is the Milage going to get better or is this the best I can expect with the driving I've been doing?

1st - 19.78
2nd - 21.88
3rd - 22.33

LibertyCRD · **Posted:** Thu Oct 20, 2005 12:40 pm

If you are putting gas in it, it's a wonder you got any mileage at all!

When I fill up with diesel fuel I always look for a station that seems to sell quite a bit of it. You don't want to fill up at "mom and pop" stores that rarely sell diesel. The diesel fuel in those places has been sitting around in those underground tanks too long. Places that sell a lot of diesel also keep fresh diesel pumping through. This is much better for your engine.

I do a mix of driving and consistently average 23.5 mpg. I'm not complaining at all because that's about 7 mpg or so better than my wife's identical Liberty with the 3.7L V6. :wink:

Ricky5 · **Posted:** Thu Oct 20, 2005 12:44 pm

Quote:

If you are putting gas in it, it's a wonder you got any mileage at all!

HAHAHAHA

Ricky5 · **Posted:** Thu Oct 20, 2005 12:46 pm

I get my gas at King Soopers by my house. They sell deisel fuel pretty consistent. I'm not complaining ... it's a ton better then my 15mpg Cherokee.

Guest · **Posted:** Thu Oct 20, 2005 1:11 pm

1st tank - 24.1 mpg average

upsized tires to P255/70R16

2nd & 3rd tanks - 22.5 mpg average

diesel engines take 10,000 miles or more to break in at which time I expect to average about 25mpg with a freeway top of about 30mpg. Time will tell...

naturist · **Posted:** Thu Oct 20, 2005 1:49 pm

I see you are in Colorado, which should get you into winterized fuel during cold weather. You will probably see about a 10% drop in mileage with that fuel, but as it breaks in mileage should improve over at least the next 10,000 to 20,000 miles. Boy, just think, when spring comes, summer fuel comes out, your ride is starting to get broken in, and you should expect to see a jump in the mileage. Can't WAIT for April!!!

grywlfbg · **Posted:** Thu Oct 20, 2005 2:10 pm

I have 3K miles on my CRD. I'm getting mid 24's during my commute - mixed City/Highway. Towing my 2,500lb 10ft covered trailer I'm getting right at 20. Haven't done any pure highway w/o the trailer.

Like others have said, diesels are still breaking in for like 10-20k miles. Mileage will slowly go up. Also, it will depend on the additives in your local diesel. Some stations also have "Premium" diesel which should have a higher cetane (energy) number than "regular" #2.

I wouldn't panic. You're probably only around 1,200 miles on your engine. It'll get better.

Also, it will help if you drive it like a trucker. Above 3k rpm you're just making smoke - very little power up there (unlike a gas engine). So figure out how to give it the most throttle w/o having the xmission kick down. It takes a little practice but will help as well.

Ricky5 · **Posted:** Thu Oct 20, 2005 3:23 pm

Sounds good to me. I was just hoping to get closer to 30mpg since the deisel fuel prices are so dang high right now ......

Almost makes more sense to drive my Cherokee every day.

kjfishman · **Posted:** Thu Oct 20, 2005 7:04 pm

LibertyCRD wrote:

If you are putting gas in it, it's a wonder you got any mileage at all!

When I fill up with diesel fuel I always look for a station that seems to sell quite a bit of it. You don't want to fill up at "mom and pop" stores that rarely sell diesel. The diesel fuel in those places has been sitting around in those underground tanks too long. Places that sell a lot of diesel also keep fresh diesel pumping through. This is much better for your engine.

I do a mix of driving and consistently average 23.5 mpg. I'm not complaining at all because that's about 7 mpg or so better than my wife's identical Liberty with the 3.7L V6. :wink:

\

Ditto that and expect better on pure highway I can get 28 on the road.

allscan · **Posted:** Thu Oct 20, 2005 8:11 pm

naturist wrote:

I see you are in Colorado, which should get you into winterized fuel during cold weather. You will probably see about a 10% drop in mileage with that fuel

My Dad had an F-250 with the power stroke diesel in it and he tracked his fuel and milage religiously and he said he got slightly better milage out of the winterized fuel. I suppose that the addative helps the fuel burn more completely, but I'm not sure.

retmil46 · **Posted:** Fri Oct 21, 2005 12:35 am

Already seen an example of one that's broke in. Had some friends in Wyoming that bought one back in February. When I went out in mid-August to help them move to the Austin TX area, they were already within spitting distance of 10K miles on it (southwestern Wyoming, a long way to go to get to anything).

They said that as they accumulated miles on it, the MPG had been gradually improving. Arounf town, they were getting 25 MPG. On the trip to TX, I spent a good bit of time driving their CRD. This was mainly interstate driving, 70 to 75 mph, with the A/C on, and it was hitting anywhere from 32 to 34 MPG.

Once that beast got into 5th gear lockup at 70 mph, turning rpm's right in the torque sweet spot, it ran on fumes. It seems the faster you go with that diesel, the better gas mileage you get.

I was so impressed with the gas mileage, and yes, the power and the torque too, 2 weeks after I got home I traded my '04 Dodge Dakota in on one.

"Geez officer, I'm sorry, I know I was doing 70 in a 55, but I was just trying to get better fuel mileage!" :lol:

LibertyCRD · **Posted:** Fri Oct 21, 2005 9:32 am

Well, I bought mine in May, and I already have 11,500 miles on it. This is my experience:

The CRD gets the best mileage when you run it under 2,000 RPM on the highway. This means stay below 65 mph! I normally exceed the speed limit everywhere I go, and my average is around 23 mpg. One time, I decided to drive conservatively to see if it really makes a difference. So I filled the tank, and obeyed the posted speed limit everywhere I went. And I never exceeded 65 mph on the Interstate. And I got 26 mpg!! So keep that tach needle below 2,000 RPM and you will get the best economy.

Also, I have noticed ZERO difference in mileage between when I first bought my CRD and now with 11,500 miles on it. So either it's still not broken in, or it already was from the factory, or breaking in doesn't change mileage on these. One of the three.

But yeah, max torque is around 1,800 RPM on these things so keep the tach there on the highway and you'll be doing well.

jc7349 · **Posted:** Sat Oct 22, 2005 4:25 pm

Running th P255 tires do they rub or do you have a lift kit ?

alljeep wrote:

1st tank - 24.1 mpg average

upsized tires to P255/70R16

2nd & 3rd tanks - 22.5 mpg average

diesel engines take 10,000 miles or more to break in at which time I expect to average about 25mpg with a freeway top of about 30mpg. Time will tell...

retmil46 · **Posted:** Sun Oct 23, 2005 1:15 pm

[quote="alljeep"]1st tank - 24.1 mpg average

upsized tires to P255/70R16

2nd & 3rd tanks - 22.5 mpg average

Ummm, a thought here. If these tires are a different diameter than the original stock, that could be throwing off the odometer and/or fuel mileage computer.

Odometers/speedometers, most any way, work by sensing how many rpm's the final output shaft of the tranny is turning. By knowing what the final gear ratio is in the differential, and the effective diameter of the tires, on an electronic version the computer can be programmed to read out that XXX rpm equals XX MPH and XXX revolutions total equals XXX miles traveled. On the older mechanical systems, you had to install the correct ratio gear on the end of the speedo cable where it hooked into the tranny, if you went to a different diameter tire you had to change the speedo cable gear so that it would still read out correctly (and prevent unwanted speeding tickets!).

One way to do a rough check is find a road that has mile markers along the shoulder (such as the interstate). Allowing for traffic, pull up to one of the mile markers, reset your trip odometer, then drive to the next one and stop. If the trip odometer is reading significantly less than 1 mile, 1/10th or more, then the larger diameter tires are throwing it off. Even 1/10th of a mile, multiplied by 400 to 500 miles on a tank, could be throwing your MPG calculation way off. You could have actually traveled 500 miles, but your odometer would only be showing 450 miles.

Only way to be certain would be to call the dealer service rep, have them check with DC to see if anything would have to be changed/reprogrammed for the speedo/odometer to work correctly with larger tires, or whether you'll just have to live with it.

oldnavy · **Posted:** Sun Oct 23, 2005 2:07 pm

Been driving diesels for years, my '83 MB diesel kept getting better fuel mileage till it hit about 40,000 mile mark and stayed steady (32 mpg hwy) till I sold it last year. Sure do miss that car, but I couldn't turn down the money.

One thing I will tell you is that you can have large variations in mpg's just from the quality of fuel you buy. These engines were designed to run on ULSD (50 ppm sulfur) diesel that 50 cetane, compared to US fuel of 400 to 500 ppm sulfur and only 42 (if your lucky) cetane. I run 50+ cetane B10 (300 ppm sulfur) fuel and when I would have to travel and use the rotgut that most here are forced to buy the VW Jetta TDI of the wife's would drop 4 or 5 mpgs on average and even top speed would suffer. One thing I have found over the years is never buy your fuel at a local Serviced Station where they do oil changes or trans fluid changes, they often dump the stuff into their underground fuel tanks, however I never had this problem when the station used above ground fuel tanks. I will not buy fuel anywhere they have underground fuel tanks unless it a have to thing.

Diesels do not like is being driven like a hearse, the VNT (turbo) will have the actuaiting rod corroade up and not allow for boost if it's not given full power once or twice a tank. The VW cars had this type of turbo and the same problem form not being rung out once in awhile, been there done that. Then there is the CCV, but I guess that should be for another time.

Guest · **Posted:** Mon Oct 24, 2005 10:18 am

jc7349 wrote:

Running th P255 tires do they rub or do you have a lift kit ?

alljeep wrote:

1st tank - 24.1 mpg average

upsized tires to P255/70R16

2nd & 3rd tanks - 22.5 mpg average

diesel engines take 10,000 miles or more to break in at which time I expect to average about 25mpg with a freeway top of about 30mpg. Time will tell...

I have no rubbing at all on paved or dirt roads. I have very minimal rubbing on the rear of the front fender wheel wheels where the pinch weld is located. Only happened once at full flex while in a partial turn - would not rub driving straight or at full turn. The P255/70R16 is amazing for my vehicle. I love it and would not change for anything. I have no lift kit.

As far as correcting for mileage difference, you have to multiply your per tank miles by 1.026 to get the 2.6% additional miles you actually travel that is not recorded by the odometer.

jeeplikens · **Posted:** Tue Oct 25, 2005 3:33 pm

allscan wrote:

naturist wrote:

I see you are in Colorado, which should get you into winterized fuel during cold weather. You will probably see about a 10% drop in mileage with that fuel

My Dad had an F-250 with the power stroke diesel in it and he tracked his fuel and milage religiously and he said he got slightly better milage out of the winterized fuel. I suppose that the addative helps the fuel burn more completely, but I'm not sure.

So, what was his MPG? I'm thinking about getting rid of the motorhome and going 5th wheel but want a diesel.

Derek Mc · **Posted:** Thu Oct 27, 2005 2:57 pm

Having traded in our CRD (a Merc engine however) Grand Cherokee with 40K under the wheels I have to say the engine in the KJ is very very tight, like others say above these motors do need over 10K to break themselves in before giving their best.
The 2000rpm tip is interesting however as that is the point the turbo is getting "on song" so it is forcing in more juice. I love the way it drives much more lively than the Grand but still very pleasing. my wife and baby daughter will travel in it almost all the time so I am delighted about the fulltime 4wd option in our wet icy and snowy winters here in Scotland.

retmil46 · **Posted:** Fri Oct 28, 2005 12:38 am

Switched over to B20 1 1/2 tanks ago, and this last top-off added 8 ounces of Power Service white bottle (winter version). So far, comparing the odometer to the gas guage, and knowing what it has done previously, looks like it's gained roughly 1 to 2 mpg this tank (300 miles at 1/2 tank compared to 270 last tank). Let's hear it for cetane boost!

oldnavy · **Posted:** Fri Oct 28, 2005 7:59 am

No gas gage in any car or truck made is accurate enough for you to be able to tell a 1 or 2 mpg difference in your fuel useage. I wish they were, but they are not. The only way to get an accurate mpg reading is with a fill up after a measured amount of miles traveled. With diesel this can be somewhat problematic because what most new to diesel people here do not know is diesel foams more then gas and the foam doesn't quickly disapate like it does in gasoline. Sometimes this can mean you can add another 1/2 gal to 3 gallons after it sits an hour or two, or has been driven 2 to 3 miles after the fill up depending on the car or truck and the way it's fuel tank is shaped and even the filler neck shape and length.

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