A couple of Fuel Questions

[RS6Steve]

I'm still getting used to my 6 but have a couple of questions that I think you may all be able to answer.

Are there gremlins drinking my fuel when it's parked up?

Every time I park with just under quater of a tank left in it, go away for a day, come back and start it the %$^*(N fuel warning comes on!

How much does it drink when it starts?

So went to fill up straight away, and today treated it to Super! 97 Octance, will not be going back to 95 and I instanly noticed the difference. So much more smoother and the power

So I can see in the forum lots of discussion around 95 vs 97, but taking it to 99, say Tesco, does it make that much more difference? and is it worth traveling to get?

97 is about 1/2 miles away Tesco 99 is about 5 miles.

[Shoppinit]

Mine also has fuel gremlins. After you fill up, does it take a lot time for the fuel guage needle to start descending?

The manual says only to use 95 octane if there's no choice and not to use full throttle with it.

You get more power / litre (so better economy) with the 99, so the extra distance will just about be compensated by the extra engine efficiency. Plus you get to drive the car for an extra 5 minutes

[RS6Steve]

Yup it takes for ever to start moving. The MFD was telling me I had 300 plus left after my 200 miles journey. Huh... no chance.....

[mushdaffer]

I would never put 95 in my car. It would be like giving a finely tuned athelete chocolate cake for breakfast dinner and tea !

Mine too has gremlins - glad it's not just me. Whenever I park the car up, starting it after leaving it in the garage for the week, the needle appears to have dropped

[Shoppinit]

The needle position and fuel computer both use the same data from the fuel level sender. However, both also have other parameters that can be set.

The range is adjusted based on fuel level and your calculated consumption over the last x miles.

The needle position uses the fuel level data and has some constants that can be adjusted so that the needle is more or less linear. You can mess with this if you have a vagcom.

[RS6Steve]

I have vagcom but it scares me... Not moved away from just checking for faults yet!

[Shoppinit]

No need to be afraid. Just don't mess around in basic settings, and always write down the coding and adaptation values before changing anything. Peasy easy.

[RS6Steve]

Will be doing lots of reading to make sure I get it right.

Thanks for the PSS9 info, it will be going on next week.

[Shoppinit]

Let us know how it goes.

[slimmyreed]

The fuel gremlin problem affects most of the RS6's i beleive. Certainly my one has them. I find that if i park up with 1/4 tank of fuel, when i start it in the morning it will be down to the red section. However (in mine anyway) if you are brave, and ignore it, i find it goes back up again after a few miles.

[ecain63]

Im not brave enough to ignore it. If she wants more fuel, i think its best to give the girl more fuel, or else she will punish you later. Can you imagine the embarrasment of being stranded on the side of the road in an RS6?!! I'd be looking for a rock to die under.

[Shoppinit]

This looks like it's fairly universal then. Nothing terribly serious, but slightly disappointing. One of the things I liked about my BMWs was the accurate fuel guage. So much so that they were able to print the actual litres on the guage rather than the cop-out E/F.

[GregR1]

I think its a common problem with all cars to be honst. My elise used to have a digital guage telling you how many litres were left from the 36 you started with. Once below 10 it would say, "refill." I used to park up with 11 litres showing, then not be able to start it the next day as it was out of fuel!

I wonder if there's something about a hot car that either expands the fuel or something like that to give a false reading.

[PoRToS]

Mine also has fuel gremlins. After you fill up, does it take a lot time for the fuel guage needle to start descending?

The manual says only to use 95 octane if there's no choice and not to use full throttle with it.

You get more power / litre (so better economy) with the 99, so the extra distance will just about be compensated by the extra engine efficiency. Plus you get to drive the car for an extra 5 minutes

How strange - I started filling mine up with Shell 99 a moth ago and the mpg seems to be dropping. I used to get around 13litres/100km earlier (with normal 98 oktane), but now with the 99 its up to 14.4 litres/100km.

Very irritating. Thought of going back to 98 now, just to check...

[Shoppinit]

Try filling up somewhere else. I've heard of petrol station owners openly admitting they put 95 in the 98 tanks.