Zoidbort

OK...so here is the lowdown, I just replaced my PCV valve and my 2006 A4 Avant Q is back to running smoothly and no more P171 codes however my gas mileage is still horrible! I know the computer may not be 100% accurate but some days I will turn on the car and drive around town and I am averaging 13-15L/100km and then other times it sits at 24L/100km even though my driving style has not changed whatsoever?
The really odd things is, while I am sitting at a light my computer will be reading 13L/100km (for example) and it will start to increase by a decimal point every second. By the time I take off from a red light my computer is showing 22+ L/100km (sometimes up to 27!?) and then it will go back down again once I start to drive (sometimes). I am getting about 180km to 1/2 a tank, which to me is a little weak in the consumption area . Do you think it might be my MAF, O2 sensor, or fuel filter? Thanks for your help and ideas on this one.

1move

iTrader: (1)

Hmmmmmm, thats a bit puzzling, why dont you try resetting the throttle boddy a couple times. I know its not directly related but might help with the readings. There are steps in the tips and tricks for your audi thread.

Zoidbort

Yeah it is pretty bizarre. I thought the Throttle Body trick was only for older Audi's and not the B7+ body styles? From what I understood it had to be done via VAG?

floodray

Here is my explanation for your car computer reading.
Your trip 1 computer calculate the short trip fuel comsumption, and trip 2 computer calculate your long trip fuel comsumption.
Trip 1 computer will auto reset after you stop your car for more than 2 hours, so when you get in the car in the morning, and stop in red light, your computer is only calculating the fuel comsumption for the last couple minutes, with cold start and stop at the light, you fuel comsumption is gonna to be high, I will say after about 10 minutes normal driving, you should be average to your normal reading, my 03 1.8T Q with cold start i usually see reading go up to 48L/100k, after 10 minutes averaging 13-15L/100k
trip 2 computer will not auto reset, it will calculate the fuel comsumption between you manuel reset it, so it should be more acuate. my trip 2 is average about 10.8L/100k city and highway
Hope this will help

floodray

My 03 1.8T Q, normally will go around 380km per tank for summer and 350km in winter.
I do a lot of city driving, and for road trip 500+km per tank. (I drive like a grandpa around 120~130)
I don't like the fuel comsumption for city driving, don't know why it go so high L/100k

1move

iTrader: (1)

No does not have to be done through the vag-com, and it works on B7's

Zoidbort

Mmmm interesting, I will check it out tomorrow but honestly I am getting 180km to a 1/2 tank...that just seems a little high IMO, no? I will do the "turn on ignition, push pedal for 3 secs, turn off ignition, release pedal, and wait 2 mins" reset in the morn and see what happens. Cheers guys and keep the ideas and info flowing!

lil1

And i thought mine was bad? i usually get 300kms for a half tank and end up with only a little under 550kms on a full tank. Being a four litre i was hoping for bigger numbers. I've even put in regularly fuel injector cleaners but only with a bit of luck.

best of luck to u bud

samram1972

I find my consumption a bit low. I have a ix of h/way and city driving, but the most I have gotten so far is 450km, on almost all h/way km's. Normally I get about 400km per tank, which I find low - I was hoping to get 600km on my 1.8T Q 04, but NEVER close to that.

I am a bit aggressive, but even when I drive calmer I get about the same. Any ideas if this is norm or should I be hitting bigger numbers?

Stevelev

Hmmm ... on my B6 A4 (with BT), I rarely got less than 400 kms to the tank in the city. The B7 S4 wasnt quite as good and you dont know what poor city gas mileage is until you spend some quality time at the pump with an RS (no complaints though!)

I wouldnt spend too much time focusing on the cluster readout as sometimes you can even get this WITH a check engine light: