Hi, is it normal that the fuel consumption readings on an NC (2.0 2010) can be extremely different ?
While my driving style (especialy during the observation period) is consistent, the reading varies from 7.9 to 12.5 liters/110 kms.
I live in Almeria/Spain and its fairly hot by now, the observations are off course made when the oil is at the right temperature.
That seems a bit odd. I have a 2011 NC and mine stays pretty consistent if Iām cruising. Mines in MPG (UK), but converted Iād say on the motorway at 70 I sit between 7l/100km - 8l/100km. If you keep resetting it, you will obviously see it jump around a bit, but over a full tank mine will usually settle in somewhere in the middle of 7 - 8.
Have you tried tracking it with an app? I use fuelio, but there are a ton where you enter in the mileage, price of petrol, and how much you put in. Could be interesting to see if the car is actually running poorly or the sensors just bad.
Thx, was yours a 1.8 or 2.0 ? Might make some difference but 12.5 (sometimes) seems excesive, i will have to follow this up. No Mazda garage in the neighborhood hereā¦
Where is the water temp gauge sitting?
Not unusual on these to develop a sticky thermostat, which can then leave the car in warmup cycle and get through a lot more fuel.
Thxā¦well the water temp never looked like something to worry but i will keep an extra eye on the movings, done some research and indeed; the thermostat can be sticky on some (mineās a 2010 with 150.000 kms ). Wiil double-chek the water temp gauge readings.
This is an interesting thread, as my NC 2.0L Powershift is giving me great returns. On a run I get over 40 mpg and on a recent trip from the South Coast to West London I acheived 48.4 mpgā¦loving the long legs of the 2.0L, together with the 6 speed Powershift Gearbox, which I believe gives it the edge 
Just a thought.
You could buy a cheap ELM327 bluetooth obd dongle and install the TORQUE app on to your phone.
This will allow you to get real time data from the ECU.
This is how I found out that the cars temp gauge is not very accurate.
The engine temp seen by the ecu was only 65c but the gauge was showing normal.
The car was only doing 26 to 28 mpg
After changing the thermostat - I now see a regular 80 to 89c engine temp even though the car water temp gauge still reads the same.
Now I see 36 to 44 mpg
This is the torque app installed in my chinese head unit
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Forget the temperature gauge. Get an obd2 scanner and read it from the sensor directly. A bluetooth obd2 dongle can connect to your phone and give the ecu reading rather than the mega vague reading from the temp gauge.
It should read about 80 to 85c and warm up really quickly in summer
Edit. Someone beat me to it lol
Just to add. The economy meters on most cars is laughably inaccurate. The only way to judge for sure is to fill up and track your full tank mileage, when you fill up again youll have a proper result.
People claiming 40+mpg out of their 2 litre mk3. How? Ive never got more than 36, and i only got that once. Normally 33mpg is my average
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Steady run in convoy to the national meets using cruise control gets me 40+
Typically - like you I see 34mpg as a weekly average
Thx all, in the first place i think i will stick to that āold schoolā method. Filling it up ; drive 100 kms and filling it up again. Also strange that if the thermostat would āstickā then the reading should be consistent no? Not showing (example) 7.2, 9.6, 10.2 then 8.2 ā¦when off course driving at same speed/manner. I believe the consumption should be high but consistent with a sticky thermostat no? I might be wrong as iām not an expert in these thingsā¦
I canāt be a---- to convert litres to gallons/km to miles (even though we buy the stuff in litres) we do mpgš
My NCās NC1 and laterly NC3.75 did around the same mpgs long journeys if lucky around 37 and 39 respectively mpg, short around town country lane type journey low 30ās to at best 35 in the later NC. To achieve anything like the above it would be no caning it, which I very rarely did anyway.
Autos should return less mpg than a manual I guess, would that be true of the NC power shift?
Iām impressed with the MPG that some people here achieve.
On my current (supercharged) 25AE, Iāve averaged 26.42mpg (over 3,837 miles). On my previous (bog standard) Mk3.75, I averaged 29.66mpg (over 4,630 miles).
Both figures calculated using a spreadsheet where I record all fuel/miles, so not paying any attention to the dash readout. I only use Shell V-Power.
My Powershift in auto reads an average of 26-28mpg, but that is mainly short journeys with occasional spirited drives. Dropping the box in to manual mode for the above returns around 22 
but clearly not scientific and given my low mileage, not an issue.
Tomorrow have a sedentary 180m round trip, see what that does.
Yes, to clarify, short journeys will bring the figures I acheived down dramatically. The run I acheived 48.4 mpg was a mix of B-roads, Motorways (M3 &M25). There was a mix of speeds between 50 through motorway roadworks and 65/70mph and occasional higher speed wehn overtaking. Certainly keeping a contant speed obviously helps and not bing too heavy on the gas but as the 2.0L is a very willing engine, that is not an issue. I am very lucky in that my engine has only done 20k miles and regualrly serviced, so just run in reallyš
My experience over 45+ years of driving, is that 2.0L engines by design have been more economical than 1.6 engines, as they are not working so hard. However, modern engines with Active Cylinder Technology and DSG gearboxes etc do acheive great economy, combined with better fuels and incredible ECU technology, where they can be programmed for economy or performance.
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@b_w: A quick update on this subject for you, as follows;
We have just returned from 4 days at an MX-5 gathering on the Isle of Wight (IOW) for the IOW Car Show on Saturday and an Island drive with IOW Group on Sunday.
I filled up my Mk3.5 PRHT Powershift and zeroed the trip computer straight away, on the way to the Portsmouth Ferry on Friday 6th Sept, which is only 12 miles away from us. We have just got back home tonight 9th Sept and looking at the trip computer we drove 211.4 miles and acheived 29 mpg.
Considering the only motorway element was the drive down to the Portsmouth Ferry and most of that is a fixed 50mph & 60mph the rest of the time was driving on small roads on the island, where there are no motorways and I only found one short bit of dual carriageway in Newport. The rest was B-roads and country lanes and plenty of steep hills, especially when driving down to the bays on the island.
Personally, I thought this was pretty good, given the type of driving we did and bares out that the 2.0L powershift is a great Motorway cruiser and will give good returns at contant speeds, as my 48.4 mpg reported previously in this thread demonstrated 
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Not wanting to hijack the OPs thread, but if you use Torque and an aftermarket double DIN head unit, you can find some display options in Torque for an orange display which is very similar in colour to the dash lights.
Plus, on my cheap Atoto head unit, I can choose from a range of colours to illuminate the physical buttons. Again, I chose orange.
I think it looks very OEM:
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I have to say honestly that Iāve never bothered to work mine out. It says 26mpg and Iām inclined to believe it, but other cars exist to be thrifty, if youāre retunring really good mpg then maybe you need to be a bit more āenthusiasticā when driving it 
.
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