Economy Concerns - New Fiat Doblo Maxi
 

Hi all, (also posted on fiat forums under Doblo section)

I just bought a new Fiat Doblo Maxi (105 hp 1.6 Multijet 16V) and I have so far driven it about 1200 km.

It is capable of Euro V with DPF and Start/Stop but I believe that in Singapore here our regulations are still on Euro IV so my model does not have DPF and Start/Stop.

Right now I average 6.8 l/100km (34.5 mpg) which is quite poor, but I have noticed that my idle fuel consumption is slightly high for a diesel.

With a ScanGauge, it displays my idling fuel consumption at around 1.6 LPH with AC on, sometimes dropping to 1.4 LPH (i think with alternator inactive?).

This is even worse than my previous petrol vehicle, and I'm wondering if its due to it being a new engine, or maybe the ECU is not tuned right?

On a trip with 90% highway road I can only get the consumption down to 4.6 l/100km at best.


Would you think this is out of the ordinary?

Welcome to ecomodder.

When warmed up, the idle for a 1.6L CR diesel is more around 0.5L/h.
Using AC may/will increase that a bit though.

A ScanGauge can have difficulties when working with a modern diesel engine.
Calibrate the ScanGauge first against your actual fuel consumption - measured at the pump - before drawing any conclusions based on the scangauge.
On my 1.6 Diesel, I have it set up as a 1.2L engine instead of 1.6L , and with an additional minus 16% bias, or it'd read far too high.
Actually, it still reads & calculates the average fuel consumption as being higher than it really is, while the overall fuel use is often very close to the actual volume.


Remember that it only has 1200 km, so it's not really run in yet.

Thanks for your reply euromodder, since one tank lasts so long id have to wait at least 2 more weeks before getting it calibrated well! I am enjoying the much lower running cost vs a gas vehicle though.

Over here the lowest octane petrol is already $2.1 / L, while diesel is at $1.6. ($1.25 -> $1 USD)

I only glide nice-on so I was abit worried that the poor displayed fuel consumption was due to the high idle consumption.

What consumption are you getting with your 1.6 diesel on a straight highway segment?

Around 3.5 L/100km @ 95 kph in summer @ around 20°C

Do you also use the EU fuel consumption standards in Signapore ?

Beating the tougher European standard - NEDC - means one is already hypermiling !

Hi our fuel economy labelling in Singapore is as follows:

UN ECE R101
(Revision 2) with amendment 1; or

Type 1 test specified in Annex 4 of UN ECE Regulation No. 83 and methods of calculation of fuel consumption values for motor vehicles powered by internal combustion engines only, stated in UN ECE R101 (Revision 2) with amendment 1. This includes Directive 96/69/EC or Directive 98/69/EC.

Directive 80/1268/EEC including amendment 2004/3/EC and Directive 692/2008/EC are also acceptable.

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I wouldnt think that it would be a very modern standard considering that we implemented Euro 4 for Diesels only in 2007 and we are still on Euro II for petrols, and considering adopting Euro 4 for petrols in 2014.

Anyway according to the fuel label my vehicle is rated at 5.4 l/100km combined.

I cant compare my economy to yours since my scangauge is not calibrated, but I am now trying to do cruising in 6th at around 70kph, (1200 rpm).

I used to P&G in 6th gear torque peak (1550 - 2000) going from 90kph to 110kph.

Somehow I feel that doing the P&G in 6th gear non torque peak (1200 - 1600) gives better economy, but perhaps the lower average speed -> lower aero drag overwrites the lower BSFC range im operating in?


Anyway will now just do steady state low rpm crusing in 6th to see what happens