Pegeout 307 51 Plate

[Bazile]

Had my car serviced recently - including change of air filter / plugs , which i hoped would cure an excessive fuel consumption .
I didn't realise that fuel mixtures / intake / settings , are controlled by a CPU on cars nowadays , so there is nothing that can be adjusted - I was told by the mechanic .

Would a Peugeot Planet diagnostic machine ( from looking at the internet ) be able to point to a reason for excessive fuel consumption .

[tonyav]

Probably not, unless your engine management light is on.

[Bazile]

So what do you think could be causing the high Fuel consumption - what would suggest - any ideas ?

[Graham-W]

What do you call high fuel consumption? If you are just doing short trips, in winter especially, consumption can be quite high because the engine never gets warmed up properly.
Fuel and engine size would help us make a guess into expected consumption.

[Graham-W]

eg. My dad's Ford Fusion 1.6 petrol does ~40mpg on short runs in the summer, but is only doing ~32mpg on the same distances at this time of year.

[Bazile]

Approx , 10 mile trip and a 3 mile trip daily .

1.4 cc

Fuel - Ordinary unleaded .

I'm getting low 20's mpg

[tonyav]

Right Bazile, this is what the Haynes book say's in the fault finding section. Excessive fuel consumption.
1) Air filter dirty or clogged.
2) Engine management system fault.
3) Faulty injector(s).
5) Tyres under inflated.
6) Brakes binding.

[Graham-W]

Wow. That is low, but still consistent with the short runs in winter.
Any problem like that would show up on the emissions test when the engine was properly warmed through.

[tonyav]

Yes Bazile, that is extremely low mpg.

[Bazile]

Ok

air filter has been changed and tyre pressures checked

There is no light on , indicating an engine management fault

Brake binding - what exactly is that ?

Faulty injectors - is that best checked out by a mechanic ?


You will have to forgive me - i am not mechanically minded

[tonyav]

Brake binding, that's when the brake pads ( or brake shoes ) are not fully releasing from the brake disc ( or brake drums ).
To trace a faulty injector will most likely mean having your car plugged into a diagnostics machine.

[shooty]

A dirty MAF sensor may contribute as well, making the engine run slightly rich.

[Graham-W]

Most things, other than a binding brake, would show up on the emissions test when the car is at it's proper running temperature.

[Graham-W]

Oh, yes. The other thing which wouldn't show up on the emissions test is a heavy right foot.

[derekpara]

No-one has mentioned driving style yet.

Heavy acceleration, late braking, high revs etc can all affect fuel consumption.

Good observation, anticipation, smooth acceleration and early gear changes (not too early) all contribute to more mpg.

[tonyav]

By the way Bazile I used to own a 307 my self up until a couple of months ago a 2.0 litre HDI used to get very good MPG, but it was the worst car I have ever owned, used to get problem after problem with it mainly electrical.

[derekpara]

Sorry, Graham, our posts overlapped !

[TWR]

A/Con, do you have a roof rack on the car, do you put the handbrake full down? My wife had one of these Bazile, the body size is the same on the 1600cc that engine pulls away without any problem, the 1400 is doing the work of a 1600 engine with the same weight "Result using more fuel"

[tali1]

My 307 1.6 auto did 18 mpg short journeys - my 20 YEAR town average is 22.5mpg from only 99bhpThere are V8 drivers getting better mpg than me .In my case nothing has solved the problem
As for driving style 2 of my mates have similar journeys to me - would make derekpara foam at the mouth with their idiotic driving, hard braking no anticipation wrong gear, clumsy throttle -yet their mpg is very good

[Bazile]

ok guys .

I dont drive erracticly and i'm not heavy on the right foot , so where do I go from here ?

From the suggestions kindly given so far - it looks like i'm left with the following -

1. An emmisions test
2. Possible faulty injectors .
3. Possible brake binding .
4. Dirty MAF sensor

In what order would you suggest i get the above look at ?

Also , why would late braking have an effect on fuel consumption ?

[TWR]

Hi Brazile, before you go into expense, go into your local Car Spares shop, get a bottle of REDX Injector cleaner fill your tank up & take the car for a good blow out on your local Duel C/ Motorway, If I recall, you have not had this car that long? should the Garage not sort this out for you or did you bye private?