1.6 vvt poor fuel consumption

[carlbentham]

Hi all got a 1.6vvt o5 plate 5door it averages 30mpg 26 if I boot it and about 32 if taken very very steadily this dunt seem right considering ma dad gets 38 from a 2.0 petrol mondeo with a full boot too any ideas or is it just a thirsty model

[CrumpetMonster]

Ayup,

I've got a 2004 1.6vvt and I usually get around 42mpg for my daily commute to work, 45mpg if I drive like my gran, and around 36mpg if I drive like a nutter. The journey is 25 miles, some urban, some rural, some stop starting, some coasting. This is all with a boot full of crap that I can't be arsed to clear out.

What you've described does sound very poor. Have you checked the tyres? When was your last service?

[tomalamix]

thats a big difference...does your car start normally, does it sound like a normal enine running, i.e., no shakes or strange noise working..? it was always like this?

[CrumpetMonster]

Hi again,

Just to add to yesterday; have you done the maths to see if the computer is reading correctly as it could be giving erroneous data. I normally get 490-520 miles to a full tank so I'm certain my MPG readings are there or thereabouts. Fag packet maths suggest you're getting somewhere in the region of 330 miles out of a single tank of 50 litres (manual says 60 litre capacity but I've never managed to squeeze more than 50 in).

The only other thing is, if the MPG-Ometer has either a) never been reset since you owned the car and showing the MPG of previous owners or b) is being reset too often to show how you're driving in that particular moment then the readings will be very much wide of the mark for a daily journey.

[carlbentham]

Hi all gettin about 350 to 400 per tank depending if ac is on or off it gets serviced every 10k not 20k like indicator suggests was ma mums before so not been abused. or owt and always been well maintained all tyres good, ticks over that quiet and smoothly I try start it when its already on somtimes lol. Had a stack of common probs sorted too dephaser pully, coils ect spot on car now just a shame it thinks its a scooby in the fuel department . One thing that is always on are auto lights and wipers do they put demand on engine if turned on but not running?

[carlbentham]

Its always been thirsty even before I got it never been arsed but with the price of it now its startin to make me arsed also introduction of a tracker on van meens I'm using car more so started to notice its greed now would k&n panel filter improve it

[tomalamix]

the filter should improve but the differences are proven to be irisorious. its worth to to some tests, compression ratio on each cylinder and check the lambda sensor behavior. for this last one you will need some electrical skills and equipment. depending on the results maybe you can start finding the cause of this under performance of your engine...

[carlbentham]

Its ok in performance quite quick actually for a 1.6 just crap on the juice I'm electrician by trade so might start having a look at sensors ect

[tomalamix]

ok then...here it goes. instead of explaining how to do it here it goes:

https://www.lambdapower.co.uk/diagnosis/ ... dex.asp#q9

This web site is very good to understand how the lambda sensor gives info to the ECU about the moisture air+fuel on the engine.

I believe you have two lamda sensor on your engine exhaust, the first will sens the richness of the moisture before the cat and send the info to the ECU to correct it, the 2nd after the cat, will provide info also to the ECU. If this sencond is always near the 450mV-500mV the cat is ok.

I dont know the pinouts for your lambda sensor but i believe this site can help:

https://metroxfi.com/2007/12/4-wire-oxygen-sensor/

If its not a four wire sensor google around a bit because the info is out there If needed and you cant find it lets us know to try to help further.

And here is a little bit more technical inside the lambda sensor itself before it goes to the ECU. Its bosch but other brands are the same..

https://www.bosch.com.au/content/languag ... tion_A.pdf

Meanwhile it would be good to try the engine cylinders compression also...

cheers

[carlbentham]

Sorted had 4wheel alignment done now 39mpg well happy the bloke said when he hung all laser gEar on wheels the laser was on the wall instead of target lol