Poor fuel economy on CRD

[08crd]

My guess would be the problem is a slow blocking of the D.P.F and it is only a guess.
These D.P.F are very much first generation and as such would not have had much long term testing. If there has been a major drop off in economy after an extended time, the D.P.F is the logical source of the problem.
The motor design hasn't changed and the likelyhood of fuel system, engine management or air intake(turbo) degredation over 100k(other than spool motor) is unlikely.
That really only leaves the D.P.F, my guess is the dealer gave it an out of car regen and burnt the arse out of it. To get rid of all the residual soot.
Like I said, just a guess.

[johnv]

Originally Posted by DFTD

Hi there, I bought an 08 Commander last year from perth. A friend of mine and I drove it back to Melbourne, no towing, no luggage and we sat on 95km/h. The best fuel economy we could get was 12.7L/100. At home in Melbourne my wife uses it for general running around and it sits around 14.5L/100. When we tow our tandem caravan, about 2,200 kg it sits on about 18L/100. I have been to 4 different Dealers and their standard comment is 'the computer shows no faults'. So do mechanics no longer know how to troubleshoot a vehicle unless the computer tells them where to look??? Anyway, I have spoken to others who tow and they tell me they struggle to get over 10L/100 just highway cruising and sit just over 12L/100 when towing? Compared to what the Jeep sites tell me I should be getting which I know is a bit of a sales pitch, I am way off ... or am I? To me, my fuel economy is horrible considering my previous jeep was an 06 Grand Cherokee and its fuel economy was way better. Please help.....

DFTD the fuel consumption for my 2007 GC with the same engine is similar, best fuel economy I ever had was up to 8,000 Km on the odometer when I put the 50mm ARB lift kit LRA tank etc etc into it.

If you do a lot of highway driving as I did then, it will show the lower figures of around 10L/100 however I find that normally nowaround town I get around 15L/100 and 18L/100 when towing my van.

Have you re-set your computer, so it doesn't keep averaging? If you re-set your computer when on the highway, you'll have a better reading.

I for one look forward to the 8 speed box coming in 2013/2014 - failing that Nissan have produced a very economical unit with their V6 CRD Pathfinder that has a 7 speed box, but its a bit expensive!

[DFTD]

Originally Posted by 400brad

DFTD, what was the outcome of the test from the dealership? I am currently chasing a similar problem with mine.

I do a lot of highway driving and was usually getting around 10-11 l/100 and then all of a sudden with no change in configuration or driving style the I am struggling to get it below 12.5.

I could be imagining this but the car also feels like it has a significant drop in power. It just feels very sluggish.

After I got it back from Jeep they told me that it complied and was doing just over 11L/100. They drove it for 100km then filled up the tank to see how much fuel it used. Except they did highway and suburb driving and I can only guess they did a lot of highway driving first then the last 10km back to the dealership in suburbs, driving like miss daisy. So, why they needed my car for a full week I have no idea. The car then gradually got back up to averaging 14.7L/100 around the suburbs. I have since put in a chip and it is running at a constant 12.2L/100 around the suburbs. It has been in a couple of months and so far so good. It has a lot more low down torque now so takeoff is really good. We just came back from doing approx 10,000K around WA with our van on the back and the chip was great. We were getting about 15-16L/100 until we hit head winds across the nullabor then it went up to 17ish L/100. The van is full height and weighs about 2.5 tonne. I bought the chip on ebay from Germany and it was only $130 plus postage.

[multihull]

Are you driving with your air con on?
Also you need to drive like its a diesel, drive it in the diesel torque bands not like it's a petrol engine. This will really help with economy and the life of the engine. For example don't put your foot down hard on a take off from the lights. Accelerate gradually and then when your in the torque band give it more accelerator. The other thing you can do is reset the ECU's intuitive driving tune. I'm not sure what the techo Jeep name is for this system but if you disconnect your battery negative for about 10 minutes it should reset the ECU. Then when driving reset your trip computer's litres per 100 setting on the dash. If you do the reset when coasting or down hill and no air con you seem to get a better average. Don't ask me why but just works better and makes you feel good. see how this goes for a week or two and see what you get.
Also did you dealer check the basics such as a clean air filter. Tyre pressure at 40 psi all round etc etc.

[gleeson235]

I bought a no limits chip & i'm getting 11.0 l/100 but it's mainly country driving.
http://www.ebay.com.au/itm/Diesel-Po...item3cb0ad287a