Mk 7 1.6 Tdci (95Bhp) Mpg Issues, Anyone Else?

[iNath]

Use red diesel- far more economic illegal

I was trying to work out if you were joking then Wikipedia said:

...spot checks have occasionally found as many as one in five motorists using red diesel.

:P

[KeithC]

Hi, I have the 1.25 version of the new Fiesta nad are having the same problems with poor MPG (Was getting around 42 MPG in the last model Fiesta - only aroung 36 MPG in this one!) Would it be worth trying an octane booster or injector cleaner in my car? It has only done 3000 miles, though.........

No, waste of money. The cars economy will improve the more miles you put on it.

[smudge140]

Hi, I have the 1.25 version of the new Fiesta nad are having the same problems with poor MPG (Was getting around 42 MPG in the last model Fiesta - only aroung 36 MPG in this one!) Would it be worth trying an octane booster or injector cleaner in my car? It has only done 3000 miles, though.........

[ValiantSaint]

No, waste of money. The cars economy will improve the more miles you put on it.

Thanks. Just how many miles do you have put on an engine before it is "run in"?

[Allenysm82]

Thanks. Just how many miles do you have put on an engine before it is "run in"?

10000 miles is considered a good benchmark, certainly I've noticed that the MPG and engine behaviour is much more consistent after 10000 on the clock compared to just 10!

[mikester]

I was trying to work out if you were joking then Wikipedia said:

:P

well according to those stats that would mean a few of us in this thread could be using the stuff.

:)

[StemmePilot]

What about those of us with the petrol? Mine is the 1.6L Duratec 16V Ti-VCT. Driving mostly A and country roads, without pushing on too aggressively, I'm getting about 43mpg (at least according to the computer).

I haven't yet adopted a spreadsheet but the way prices are going that might not be too far off.

[100brian]

Hi

I have a 2009 econetic 5 door live in perth australia i leave aircon on all the time and get 3.7lt per 100k or 75mpg, on the freeways/motorway speed limit is 100kph so i just select the cruise control at 100kph and sit back. around town i get 3.9lt per 100k or 71mpg.

[mark t]

I struggle to get anywhere near 40, yes I drive quick, but when I drive to work, sensibly, it does go up, once I am free of 6 side roads, and on to a main road, I have a quarter turn at the first roundabout, half at second and third, and 3 quarter on 4th, then a 30 zone and 2 40 zones, everytime I slow down, no matter who slow I accelerate, it goes down, quicker than it does up, so, really, I give up!

[iNath]

I struggle to get anywhere near 40, yes I drive quick, but when I drive to work, sensibly, it does go up, once I am free of 6 side roads, and on to a main road, I have a quarter turn at the first roundabout, half at second and third, and 3 quarter on 4th, then a 30 zone and 2 40 zones, everytime I slow down, no matter who slow I accelerate, it goes down, quicker than it does up, so, really, I give up!

You have a 1.6 diesel giving you mpg in the 30's?! Take the bricks out your shoes mate :P

[Early-1800]

Agree unless you are doing very short (less than 5 miles engine never warms up) trips across town all the time, I can't see how you could get a Diesel Fester down to less than 40mpg. Theres something wrong with either your car or you must be driving it F1 Traffic Light Grand Prix stylee all the time?

[kenny.c]

My god....less than 40mpg....!! There must be something wrong with the car.....I carnt believe anyone can drive that hard to get figures like that...!

Ken

[tvAddict]

My 1.6 TDCi (95PS) has now done 1400 miles (since June!)

I am getting about 41mpg at the moment (with all the lights, heating on) - but it is only a 3 mile trip to work.

Was getting about 46mpg in the summer.

Average speed is 18 mph - max speed limit on the roads I use is 40... and lots of traffic lights.

(and I have a delicate right foot)

Used the motorway for the first time on Boxing day - After resetting the computer, I got 48mpg at cruise-controlled 70mph for approx 40 miles.

so how do I get 70mpg? drive at 50? I'll try that on New Year's eve trip.

[iNath]

Just out of curiosity tvAddict why did you buy a diesel? You don't seem to do the mileage to warrant the extra cost.

[mrobins64495]

Iv'e had my 1.6tdci all of one day....

Done 250 miles so far to under half a tank so its working out at around 58mpg I think...

Pretty good considering I was using cruise control to manage speed, I think if I'm to use my own foot I'd get a better figure.

Plus It was a good mix of driving.

[tvAddict]

Just out of curiosity tvAddict why did you buy a diesel? You don't seem to do the mileage to warrant the extra cost.

I wanted low CO2 and high torque... I prefer driving with lower revs, and fewer gear changes needed while sitting in slow traffic.

I used to have a Mazda MX-3 V6 which had no torque, and low power until you got to about 4000 rpm... and only did 22mpg on my daily run... so wanted a change!

It wasn't that much dearer that a petrol (cost me £11.5k after scrappage in March).

[iNath]

Does anyone know if the Fiesta has a DPF? If yours gets blocked tvAddict it's gonna be very expensive to replace

(I'm not a car expert but I believe they usually regenerate after the engine is warm on a long run? If your engine never gets a good blast down a motorway it's not gonna do it much good)

[tvAddict]

Yes, it does have a DPF.

I was told it would be OK as long as I gave it a motorway blast every "now and again"... but how often is that?

I'm sure the handbook says something similar, but I can't find the section now.

I expect to go on a "long" (> 10 miles!) trip approx every 3 months (700 miles).

(Many years ago, I used to do 500 miles a week... but now have everything I need close to hand)

[iNath]

Yes, it does have a DPF.

I was told it would be OK as long as I gave it a motorway blast every "now and again"... but how often is that?

I'm sure the handbook says something similar, but I can't find the section now.

I expect to go on a "long" (> 10 miles!) trip approx every 3 months (700 miles).

(Many years ago, I used to do 500 miles a week... but now have everything I need close to hand)

Found it in the manual!

DIESEL PARTICULATE FILTER (DPF)

The DPF forms part of the emissions reduction systems fitted to your vehicle.

It filters harmful diesel particulates (soot) from the exhaust gas.

Regeneration

WARNING

Do not park or idle your vehicle over dry leaves, dry grass or other combustible materials. The DPF regeneration process creates very high exhaust gas temperatures and the exhaust will radiate a considerable amount of heat during and after DPF regeneration, and after you have switched the engine off. This is a potential fire hazard.

CAUTION

Avoid running out of fuel.

Note: After you have switched your engine off the fans may continue to run for a short period of time.

Unlike a normal filter which requires periodic replacement, the DPF has been designed to regenerate, or clean itself to maintain operating efficiency. The regeneration process takes place automatically. However, some driving conditions mean that you may need to support the regeneration process.

If you drive only short distances or your journeys contain frequent stopping and starting, where there is increased acceleration and deceleration, occasional trips with the following conditions could assist the regeneration process:

• Drive your vehicle at a constant speed, preferably on a main road or motorway, for up to 20 minutes.

• Avoid prolonged idling and always observe speed limits and road conditions.

• Do not switch off the ignition.

• Use a lower gear than normal to maintain a higher engine speed during this journey, where appropriate.

Doesn't say how often though...

[kenny.c]

My DPF regens every 500 miles (im sure all Fiesta DPF cars will be the same).....if its given the correct rpm / temp for long enough.....A good way to know if a regen is/has happened is during or straight after a regen the engine coolling fan will be on...even in sub zero air temps.... This regen cycle can take a few trips to complete if your not doing long enough trips. Only after several failed regen attemps will the ECU light the DPF warning light on the dash....

Ken

[iNath]

Mine should be regenerating weekly then! Can't say I've noticed it yet, just clocked over 8,000 miles.

[kenny.c]

iNath......what sort of driving do you normally do...? Distance / speed that is...?

I kinda "missed" a couple of my regens...when I say missed.....I mean we have been at motorway speeds and not noticed anything + the DPF has cooled down enough after the regen to not need the fan running....

The sooner I get rid of the !Removed! DPF the better as far as im concerned......

Ken

[iNath]

20 miles each way to work, 40% dual carriageway & 60% main A-road with 2 x 30mph towns. Probably average 45/50mph (not speeding in the 30! Or 60/70's for that matter!)

EDIT: Why do you want to get rid of it?

[kenny.c]

I recon your regens are going through on your work run to be honest....I dont really know how long a regen takes.....but my run to work is 12 miles, 3 miles at 30 to the motorway then 70mph for the rest and a couple of times when ive got to work the DPF has regen'd and the cooling fan is running and there is a smell of "HOT" when I get out of the car and lock it.

There is a differential pressure sensor which looks at the pressure across the DPF which is used.....

1 - For starting a regen if the filter becomes blocked before the 500 mile regen starts

2 - Monitors the pressure during regens to tell the ecu when the DPF is clean

3 - Or both of the above...

Im lead to understand if the car is driven with some decent revs and speed in the 500 mile "window" the filter wont be as blocked as a car just town driven....so the regen time is shorter. This "problem" with blocking DPFs in town driving does explain the poor low end throttle response on the 95ps engines.....as most none DPF engines emmit a "POOF" of smoke when you put your foot down from low down due to slight over fueling to achieve good throttle response...which would block a DPF pretty quick.

My reason for removing it to release more power and throttle response + tuning becomes easier with better results....ive actually removed it once and fitted a "modded" focus DPF, throttle and power was noticable but the ecu light came on....which we are assuming is beacuse the pressure sensor needs to see a minimum pressure across the DPF which represents a clean filter......a solution to this is being worked on as I speak.....

Ken

[tvAddict]

Thanks for all the info.

I have definitely noticed the fan staying on quite often when I stop.... even in this cold weather and on 3 mile trips... so it must be doing it's regen.

Have now done 2 x 100 mile round trips on motorways so it has now had a bit of a "blast".

Managed 50.6 mpg at cruise-controlled 64 (69 on speedo, 64 on GPS) in no traffic for 40 miles.

Don't like going that slow though! I think I overtook one caravan, but everything else was whizzing past.

Think I will now forget about economy, and go back to normal driving style, and just get 40mpg but feeling happier!