Author Topic: 147 JTDm Bad Fuel Economy  (Read 3680 times)

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mediocregr

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147 JTDm Bad Fuel Economy
« on: October 11, 2018, 12:01:48 PM »
I have owned my 147 JTDm for almost a year now, it has 154XXXkm on the clock and runs fairly well. However, throughout my whole ownership, I have noticed that with a mix of urban and semi-urban driving I average 7.8L/100km which seems absurd when some people flaunt averages of 6l/100km. I don't drive the car hard, shift at just above 2k rpm, smooth on the throttle and lift going down hills.

Would anyone know what could cause such high fuel consumption on what's meant to be a very efficient little engine?

Cheers.

alphahall

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Re: 147 JTDm Bad Fuel Economy
« Reply #1 on: October 11, 2018, 12:12:32 PM »
Hello, I have a very similar car (2006 model 147 JTDm, 161k km).  In purely urban stop start driving, we get a very consistent 8.2 l/100 km, measured at the bowser and odometer, not on the trip computer.  I think the average speed the trip computer records is under 25 km/h.

The trip computer shows 6 or less on a club Sunday Drive like the one to Marysville and Warburton a couple of weeks back.

(Our petrol Pajero records basically exactly double the consumption in urban and rural runs for comparison.)


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CitroŽnbender

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Re: 147 JTDm Bad Fuel Economy
« Reply #2 on: October 11, 2018, 12:15:53 PM »
That doesnít sound overly bad for a (ten year old?) car.

Have you confirmed wheel alignment, tyre pressures, suspension health? Have you checked the figures with fuel receipts vs odometer? How is the thermostat?

Are you driving on coarse seal or otherwise rough roads at all?

Craig_m67

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Re: 147 JTDm Bad Fuel Economy
« Reply #3 on: October 11, 2018, 03:09:28 PM »
Check the thermostat first.  The engine will overfuel until it reaches temp.

Is there any loss of power, flat spots etc?

Check for air leaks on all boost, air inlet hoses
Check/clean the MAF
Check/clean the MAP sensor

Does this version have swirl flaps, EGR, etc.. what condition are they in?

I drove a 1.9JTD from 2006 through 2018. Hugely reliable. Only time fuel economy went through the window was when the thermostat was buggered (I went through 4 in 200K km)

It would return 900~1000km per tank regardless of how I drove it
'66 Duetto (lacework of doom)
'73 1600 GT Junior (ensconced)
'03 156 1.9JTD Sportwagon (daily driver)

bazzbazz

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Re: 147 JTDm Bad Fuel Economy
« Reply #4 on: October 11, 2018, 03:13:33 PM »
Just out of curiosity you should check in with the new user and see how the old girls is going.  :)
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mediocregr

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Re: 147 JTDm Bad Fuel Economy
« Reply #5 on: October 13, 2018, 11:40:49 AM »
Hello, I have a very similar car (2006 model 147 JTDm, 161k km).  In purely urban stop start driving, we get a very consistent 8.2 l/100 km, measured at the bowser and odometer, not on the trip computer.  I think the average speed the trip computer records is under 25 km/h.

The trip computer shows 6 or less on a club Sunday Drive like the one to Marysville and Warburton a couple of weeks back.

(Our petrol Pajero records basically exactly double the consumption in urban and rural runs for comparison.)


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Yep this is similar to my consumption in stop, start traffic. When driving in the country (even through twisties) I can still get around 6 so possibly these cars just use a lot of fuel in the lower rpm stop start traffic

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mediocregr

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Re: 147 JTDm Bad Fuel Economy
« Reply #6 on: October 13, 2018, 02:44:34 PM »
@CitroŽnbender Yeah she's getting older now that's for sure. I haven't checked the suspension, however, I just had a service done so I suspect they would have checked. I check my economy with an app every time I fill up with the odometer reading etc.. I haven't checked the odometer yet and mostly sealed roads.

@Craig_m67 In terms of power it's still nice and linear with higher boost at 3000rpm, Hoses have just been replaced, EGR Valve was replaced 5000ks ago. I'm hoping I just need to give the MAF and MAP sensor a clean. Currently, I get 830ks from a tank regardless of how I drive it.

I've been driving the car more efficiently the past couple of days and I've managed to get the consumption down to 7l/100ks with a few long distance, minimal traffic drives.