What’s the deal with my AU's fuel consumption?

[peterljohnson55]

I really don’t think I am getting reasonable fuel consumption, so perhaps some can give me advice on what I should do.

VEHICLE
3/2001 Ford Fairmont Ghia AU2, Tickford 6 cyl, 4L VCT.

HISTORY
Engine has done 153,000 kms. Engine runs well.
At 139,000 new leads, plugs and coil pack were fitted.
Oil changed every 8000kms about.

THIS YEAR
The following figures are very accurate….
Have travelled 3,200kms: of which 2200kms is city and suburban; and 1000kms is Freeway driving, where I normally sit on 100-110kph.
My driving style is relaxed and not aggressive.

FUEL CONSUMPTION:
450 litres of E10 for those 3,200kms
= 14.06 L/100kms (69% is city and suburban, 31% freeway).
To me this seems very high, especially given freeway component, but I cannot figure a reason for it being so high.
I think 10 or 11L/100km would be more reasonable.

I AM LOOKING FOR IDEAS ON …
- why the consumption is very high?
- any economical ways to improve consumption ?

Your interest and advice is appreciated, with thanks.

[jpblue1000]

I wouldnt say your consumption is Very high. More like the high end of normal.
E10, I believe, is partially responsible, as for the same energy you need more of it. about 10 percent extra.
JP

[Bushbasher]

When was the last time the oxygen sensor was changed?

[revcore]

The VCT engines tend to drink a bit more than the regular 6 but that consumption rate seems about right I reckon.

[Maka]

Hi Peter, air / fuel filter & o2 sensor been replaced recently? E10 is no where near as good for mileage compared to 91ulp (near 30% less mileage in my AU). Maybe switch back to 91ulp to get better fuel economy, what viscosity oil are you running? I replaced my stock intake tube for a BA intake & got .8 of a litre improvement in fuel economy. My tyre pressures are 38psi all round. My fuel economy is around 11.8l city & 7.8 hwy if driving sedately.

p,s - stock combined fuel consumption figures for a vct ghia combined are 10.5l/100

cheers, Maka

[Bill M]

How long have you owned the car? Has the fuel consumption got worse?
I have owned an AU VCT 6 since December 2001 and the figures you mention are about right. I get around 10L /100km on the highway and 13-14L city cycle. I am of the opinion yours are in the normal range.
The original mandatory fuel consumption label on a VCT 6 in 2001 stated 12.5L/100km city cycle and these figures were generally considered optimistic.

[XRGhia]

Sounds about right. I was getting around 12L/100km's on the freeway to work (about 85% of the trip), and 16L/100km's local driving.

...mine weighs 50kg's under 2T, so i'm not one bit complaining especially from a heavy, but comfortable car.

[OffRoadFalcon]

From what I heard on these forums, the VCT I6 drinks a good deal more than the Intech I6. In some more hwy driving situations more than the Windsor 5.0 V8.

Note: we were talking generally about Fairlanes though, not Fairmonts.

[XRGhia]

^^ on the subject of VCT fuel economy, when I had the AU VCT 4L and 5 speed in the EF Wagon, I was getting around 8L/100km's on the freeway and 10.5L/100km's driving it really hard around locally.

It's the weight mainly that causes the fuel economy to be crap. More weight = More acceleration = More fuel.

[FERG_51]

Get a fuel pressure test, my bet is it will be high due to a blocked fuel pressure regulator. Common fault with AU's. 10ls per 100 is what you should be getting at least on highway.

[Maka]

The original mandatory fuel consumption label on a VCT 6 in 2001 stated 12.5L/100km city cycle and these figures were generally considered optimistic.[quote] Bill M

Interesting tidbit from Carsguide -

DID YOU KNOW?

"Betcha didn't know the figures on fuel consumption stickers are based on Premium Unleaded 95. If you're like me, you just go looking for the cheapest fuel you can find when it comes to fill up. That's fine, but it means you're never going to see anything like the manufacturer's claim. Sucks doesn't it? The reason the test is based on Premium 95 is that not all cars will take standard unleaded, especially European cars"

Oh well, now we know why fuel consumption can be a bit of a merrygo round in certain older Oz built cars lol!

cheers, Maka

[peterljohnson55]

A very big 'Thank You' to everyone of you for your contribution.

Here is my plan:
1) Give 91ULP a test, over 1000k, same conditions, ASAP, (costs about 3% extra). I think this is the thing that will make the difference.
2) Get all the crap out of the boot - could be 20ish kgs (1% of car weight)
3) Check for fuel pressure regulator blockage
4) After tests consider new oxygen sensor
5) Consider replacing standard intake with BA intake.

For those who want more info, here it is...
- OIL: 10W30 synthetic
- TYRES: 32 to 38.
- CONSUPTION over time, getting worse

[Maka]

Sounds like a good plan Peter, good luck with it - if you need any advice concerning the BA intake let me know. I'm looking foward to the e10/ 91ulp test, it'll be interesting!

cheers, Maka

[dieseltrain79]

Probably needs new intak manifold gasket if not already changed .

Our VCT Fairmont GHIA averages. 15l/100km round town & 10-11 on highway use . There's always 2-3 on board and boot full of kiddy stuffs

[raa4.0l]

Nobody's mentioned it but how old is your cat and exhaust system as they degrade over time and cause your economy to suffer.

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