areg321

Hey guys... New to this forum made my account 5 minutes ago.

Recently purchased an Audi S6 2007 at 124000km. And by recently I mean yesterday.

When i was driving around speeding and what not it was saying that I'm getting 12-14 mpg which seemed normal to me.

However, today, I turned my car on and drove today only to see my mpg gradually drop to 7?! I thought it would come back up but no matter how i drove, fast or slow, the mpg remained at 7mpg.

Any opinion counts.

91quattro

How are you measuring mileage? Number of km between fuel fill ups?

areg321

Thanks for your quick reply. Ive only filled up gas once and therefor have not had the chance to measure gas mileage manually; hence, I am referring to the gas mileage input the car shows you on the go.

twopedalwarrior

Hey

Congrats on the purchase. I presume you have the 3.2l FSI engine?

Either way couple of things.

1) you run 91 octane in these things, no less or drives like a putz. Knocking etc, reduced milage etc
2) Presuming the car hasn't sat for a while and its not bad gas, pull the plugs
3) Plugs are cheap and would be the first step in looking at their condition. you can google photos to compare you plugs
4) O2 sensors, you didn't mention a check engine light so may not be an issues
5) do you have a vag to scan for codes?
6) start with plugs

areg321

I have a 5.2 V10 engine. I put 94 octane. Im guessing your talking about the spark plugs? If so, I will surely have those checked. Also, im not sure about the O2 sensor, but i was going about 70 mph yesterday in the city (accelerated fast) and the engine sounded and felt great but the check engine sign started flashing.. Had it checked this morning code said it was just the gas cap that wasnt tied down properly, dodged a bullet there. Also, oil level was at minimum was missing 1.5 L of it thanks to the dealership that sold it to me (no leak, they just have a bad mechanic).

areg321

Oops, i meant 91 octane not 94.

91quattro

I would fill it up, note the odometer reading, drive the tank down to 1/4 or below, and fill it up again and then do the math to figure out mileage. I am getting 14-15 mpg on my 07 S6 5.2L, and am changing the spark plugs next week - first step. But mid-tens for this car is pretty normal, especially if you can't resist punching that motor from time to time (like me).

Also, I would replace the fuel filter if you haven't done it in a while (or ever). Just changed mine, it was the original, so 10 years old. Located just in front of right rear wheel. An easy DIY and it definitely made a difference in mileage and smoothness of acceleration. Also should lengthen the life of the fuel pumps.

areg321

Thanks for your valuable input. I will soon be changing my spark plugs and my fuel filter.

Also, i noticed that the car doesnt accelerate properly, but that could also be caused by my lack of experience driving V10s. When it is on drive (no sport mode), i have to press the pedal a good amount before the car responds. Dont know if thats normal.

twopedalwarrior

I read earlier that you said that your check engine light came on, have you scanned for codes yet?

twopedalwarrior

Also I would suggest to take a look at your MMI settings for the dynamic driving features, that may change the performance