MPG Ford Fiesta Ecoboost very low

FlyingDonkeys

Hi I'm driving a Ford Fiesta Ecoboost 5 door and put in 2.4 gallons when showing empty with 3 miles to go. Now 42 miles later its showing empty with 13 miles to go.

Thats way less than the advertised 61 mpg. Does anyone know if the city stop thing where engine cuts out if you dawdle uses up petrol. I remember being told switching engines on uses a lot of petrol so better to idle.

I like the auto stop as its better with air but really puzzled by low 23mpg and will have to change cars.

facade

Relying on the gauge/light and a small amount of fuel won't give an accurate figure.

You need to brim the tank, do about 1000miles, keeping a record of the exact amount of fuel you add, then brim the tank again.
Divide the mileage by the exact number of litres of fuel added (not including the first fill up obviously), then multiply by 4.546 to get MPG.

However, if the light comes on after less than 200 miles from a full tank, you have a problem

The ecoboost is a teenie weenie engine with a biggish car, and a turbo to really shove the fuel through if you have a heavy foot, in the real world, expect anything from mid 30s to low 50s depending on how you drive it.

I presume you have checked the obvious- the tyre pressures are correct, and there isn't a brake stuck on.

FlyingDonkeys

Thanks yes, done the obvious. Must have a heavy foot! Cheers

Kernow666

mine averages just over 50mpg per 1000miles , i do about 100miles a week and average less than 30mph although i am not heavy on the acc or brake

bigjl

Do tank to tank comparisons.

Similarly to the Fiat 500 Twinair if you drive any capacity of small turbo charged petrol engine you will go through petrol.

forgotmyname

What speed/revs do you change gear at?

As mentioned though, you need to check from empty or full tanks.

You can run it down to the redline or when the trip says x miles left, but you need to repeat that several times to get an accurate figure.

Putting in 2.4 gallons wont be accurate at all, The gauges will vary depending on the camber of the road and if its on an incline as well as temperature variations.

Indout96

Wife has a Focus with the 1.0 (125 bhp) engine, on a reasonable run it averages mid 40/ low 50 depending on traffic. around town she gets low 30's
As the Fiesta is smaller / lighter I would expect a bit more.


The stop start will save petrol if used correctly, collected wisdom says if you are stood more than 3 seconds you are saving fuel using it.

AdrianC

FlyingDonkeys wrote: »

put in 2.4 gallons

So you actually put in just under 11 litres? Or did you put in just over 9, and found a US litre-to-gallon conversion...?

If you're bothering to drip-feed the tank like that, can I guess that you just do short local journeys?

Strider590

Small engines are only good on fuel if driven slowly and in stop/start traffic, as soon as you try to drive at a reasonable pace, the economy falls right off...... Add to this a turbo and basically as soon as it spins up your MPG is going to go right out of the window.

When I drive a small engined car, I end up thrashing the nuts off it, JUST trying to keep up my normal pace.

bigjl

If you want a good example of how to get rubbish fuel economy out of a Fiesta Ecoboost have a watch of the TG episode in Ukraine.

Captain Slow drove with high RPM and pulled some wires to get the engine light on but still had loads of squirt left.

Hammond adopted the heavy foot lots of boost tactic and used the petrol up in no time.

almillar

put in 2.4 gallons

Yeah, you're wasting petrol getting poor MPG spending all your time driving through petrol stations! I know it's nearly pay day and all but that's just not a representative distance.