I have a 2007 Fiat Doblo 1.9 Multijet 120hp with 52,500 miles on the clock.

I did a motorway trip doing 70mph on a round trip of 430 miles at the weekend and the trip computer tells me its only doing 41.5 (way back) or 43.2 (way there)

This was driving steady with not much traffic at a fairly constant speed, I think this is a little low as I was expecting figures of 48-50 mpg.

Tyre presures @ 35 front and back, recently serviced at Fiat about 1000 miles ago and they also reset the oil degradation counter (I have fiat ecu scan). When I last checked the DPF was 20% clogged 'no clogging' it was at 50% when I bought it but I do close on 1000 miles a month on fast a/b roads and motorway so it has cleared its self out, it had done 1 regen.

Do you guys thing this is low or what to expect in real world figures?

I have a registered version of fiat ecu scan and associated cables, so I can montitor and view most paramenters if there is something I could check and log while driving to see if there is something wrong?

The trip computer tends to underestimate. Only way to accurately work out MPG is brim your tank, do your trip then brim your tank again. Use on of the many online calculators and enter the distance travelled and the amount of fuel you put in (which of course will also equal the amount of fuel used for the journey) and you'll have your true MPG.

Or sign up to Fuelly and let it do it all for you

Signed up for fuelly, looks pretty good!

Is there any maintaince I should check, like egr been stuck open or closed, clogged hoses, etc

The 120 does tend to be jucier than the 105, I guess all that extra bhp comes at a price?
Also, as said, best to ignore the trip & work on actual figures.
I have noticed with mine (105) that if I drive sedately, really gentle accelleration, get to 4th asap etc etc I can get better mpg whereas if I were to simply rev the engine whilst sat at the lights, the fuel guage seems to move accordingly - almost as if that rev cost a litre of fuel !

Ive just added my first fill up on fuelly, so we shall see what happens over the coming weeks.

I dont particulary find the 120 particulary 'engergetic' it seems fairly flat throughout the rev range, doesnt really have a shove when it comes into the peak torque band etc which I why I suspect there could be something a miss...is are the multijet's fairly flat throughout the rev range?

my 07 plate 120 multijet taxi is returning 41 mpg ,this is worked out brimming the tank and using torque cars mpg convertor to work this out,this is 3 mpg up after doing a full service,all filters ,correct oils etc.my old 105 doblo taxi was doing about 44 mpg on the same runs.

My 59 plate 120 has returned an average of 38.1 over the last 15k miles. I measure it at each fill and the best ever was 46.03 and the worst 31.46. I try and fill up at the same pump each time and have always used BP Ultimate diesel and believe the differences above are purely down to driving technique and journey type. The car has only covered 22k miles so it is possibly still bedding in but the higher of the two readings above was achieved by doing such things as slipstreaming lorries & coaches on the motorway and coasting down hills (neither of which I would recommend but I just wanted to see how much I could possibly get). The trip computer always comes back with a figure around 42 mpg, the warning light always comes on at around 400-430 miles and I really daren't try form for than 500 miles or so on a tank (got 530 the other day and managed to get 59+ litres in the tank).

my taxi has 24k on the clock,hoping it gets better with more miles under its belt.my old taxi the 105bhp doblo had 160k on it when i got rid of it because although the engine was sound ,rest of car was tired.

The reason why I questioned the motorway economy was because on my 80 mile trip each day on a 70mph ring road and round abouts and a and b roads the computer average reading is 42-43mpg, so I was expecting to see an increase on the motorway with it been a steady 70mph and cruising, rather than stop start round abouts, hills, junctions, traffic lights, 30/40/60 varying limits, twists and turns on country roads.

i dont pay attention 2 the trip on my doblo,never seen a trip on any car work properly, best 2 fuel up your car 2 the neck so u cant get anymore fuel in ,take a note of the miles on the clock,drive it a week or so and fuel up again 2 the neck again,work out how many miles u have done and use a mpg convertor which will ask for the miles u have done and the litres of fuel u have used,which u will get off your fuel receipt,thats the only way u will get a accurate reading of your mpg

Petrol Doblo MPG Info:

Mine does 33 mpg, seemingly no matter how I drive it. The "cost per mile" (more meanginful as unleaded is cheaper) works out at 18.5p. But God, the 1.4 petrol is slow. Every now and again (when I am plodding along the slow lane) I think about getting another 1.9 JTD. Then I remember the £1,500 I spent in 3 months on my last diesel Doblo and just keep poodling on.

On my soapbox again.... get rid of the DPF it stifles your engine and it will only regenerate so many times. In brand new form it restricts gas flow, so imagine what it's doing 20% blocked, our Doblo's are averaging 51.9 mpg mixed driving.....

citds said:

On my soapbox again.... get rid of the DPF it stifles your engine and it will only regenerate so many times. In brand new form it restricts gas flow, so imagine what it's doing 20% blocked, our Doblo's are averaging 51.9 mpg mixed driving.....

Click to expand...

I've read a lot of 'stuff' on the old internet forums regarding dpf removal.

Considering im doing 80 miles per day, on 60mph A roads, up hills, and fast 0-70mph ring road roundabouts, my DPF is still ranging from 25-40% blocked depending on when I check (i.e, if its regenerated). You would of thought that the dpf on my vehicle would stay fairly unblocked considering the mileage im doing - Although, I guess it depends how much 'damage' was done to the dpf in the first 50,000 miles before I purchased the vehicle, maybe its trundled around town all its life. Its also annoying how you do not know if/when its regenerating!

Its something im activly looking into removing the dpf and having an economy map or 'performance' map installed to remove the dpf entirly.

Our 09 120 mjet with 20000 at best has returned 42.9 according the computer down the motorway. Around town stop starting it says its doing 39 on average with normal motorway returning 41.

We have the three fiat roof bars on which will cause some drag I guess, but otherwise yours sounds to be giving similar figures.

Any info on dpf removal would be good. I've read that a re map needs doing?

Did a short run on thursday and when I got out of the car, it smelt funny, like something really hot. I figured it was in the process of, or just finished doing a regen.

Plugged in fiat ecu scan, and the distance since the last regen was 49 miles which tallies up with the milage ive covered since then.

Problem is, the DPF is 55.07% blocked, and it only regenerated 50 miles ago!

Ive done 2 fuel ups now, Fuelly is saying 35mpg!!!! Surely something a miss here now.

doblodog said:

Did a short run on thursday and when I got out of the car, it smelt funny, like something really hot. I figured it was in the process of, or just finished doing a regen.

Plugged in fiat ecu scan, and the distance since the last regen was 49 miles which tallies up with the milage ive covered since then.

Problem is, the DPF is 55.07% blocked, and it only regenerated 50 miles ago!

Ive done 2 fuel ups now, Fuelly is saying 35mpg!!!! Surely something a miss here now.

Click to expand...

Have you checked you brakes are working as they should? I had a seized brake on an old car which made a burning smell. There were no symptoms on out of town journeys, but city driving the pedal went to the floor.

A bit risky but you could spray some water on your brakes when you stop to see if any on all of them are over heated. You will turn to steam and sizzle if so.

Maybe a long shot but it would lower your mpg.

Brake pedal travel *seems* ok but I'll check for binding brakes.

The smell and distance since the last regen would coincide with when I smelt the snell though