Audi A4 B5 1.6 - poor mpg - anything i can do?

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Thu 6 Jan 2011 08:18
Audi A4 B5 1.6 - poor mpg - anything i can do? - foshizzle
I have an Audi a4 1.6 petrol manual, and its giving really over the top figures for poor mpg. I put £20 in last week and i got 90 miles until the light came on again.

@ 122.9 a litre, 90 miles, £20 spend works out for me at 25.14mpg.

I drive it to work on a morning and drive it back. Its not spirited, just a steady trundle at about 50 miles an hour all the way for about 9 miles.

The tyres are all pumped up, the only thing i could think of is that there is a slight misreport as i have 19" wheels on it, but surely not this noticeable (maybe a few miles out).

Is there anything i can do to the car to ensure i get the best mpg engine wise, and aside from checking for fuel leaks?

Many thanks.

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Thu 6 Jan 2011 08:46
Audi A4 B5 1.6 - poor mpg - anything i can do? - elekie&a/c doctor

It may be worth having an engine diagnostic check to see if there are any faults logged .All Vag models suffer with engine coolant temp sensor problems that can cause overfuelling situations as they give an incorrect reading back the engine control unit.Also is the engine running up to the correct temp?(thermostat).hth

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Thu 6 Jan 2011 10:58
Audi A4 B5 1.6 - poor mpg - anything i can do? - foshizzle
hi thanks for your reply. Ive got a VAGCOM cable and nothing comes up error wise for the engine, and its running at normal temperature. I just thought that the figure of 25mpg was ridiculous, but it may just be normal?

I might give the coolant sensor a change just to see if it gives me any change but its clear on the engine sensors for faults.

Ive also got a new dizzycap and rotor arm to go on - would this make any difference?
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Mon 17 Jan 2011 07:47
Audi A4 B5 1.6 - poor mpg - anything i can do? - foshizzle
I changed the rotor arm and dissy cap but got no change. I put £50 in it the other week and got about 240 miles, which for a 1.6 is terrible.

Vagcom codes are clear but is it worth changing the CTS to see if its misreporting? There is two, and as its going from fast to slow idle properly im predicting it may be one of the two.

Aside from this is there anything else?
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Mon 17 Jan 2011 10:58
Audi A4 B5 1.6 - poor mpg - anything i can do? - Peter D

If you have Vagcom you need to look at the live data to what temp if the ECU is seeing. There is only one sensor with two elements in it. One for the guage and one for the ECU. The other sensor you refer to may be the Fan thermal sensor. £'s of fuel and distance makes no sence at all. Regards Peter

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Mon 17 Jan 2011 13:44
Audi A4 B5 1.6 - poor mpg - anything i can do? - Steven Quas

To find out the real economy you really need to measure the distance between completely full tanks, otherwise you risk trying to solve a problem that isn't really there. The fuel warning light may not be consistent in when it gets triggered - going up or down a steep hill, round a sharp bend may affect it.

If you are really getting 25mpg then it does need investigating of course.

Steven Quas , Hamburg

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Real MPG enables you to register the fuel economy you are actually getting against your make and model of car, its engine and type of transmission.

Every time you enter an average consumption figure against your car, the overall average automatically adjusts to reflect it.

Real MPG

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