poor gas mileage

[bagher]

bone stock, 48.xxx miles, mostly city driving, getting 15mpg. what could be the culprit?

[illegitimus]

I have the same car but 06 and am getting pretty poor gas mileage, about 19mpg mixed driving (70/30 - city/highway). I've done a few things to the car including spark plugs and coils replacement, pcv valve replacement, had fuel/air induction service done. I also need to replace the tires: they are noisy and the thread wear isn't even, although suspension seems to be fine. I am going to check the fuel economy on my next fill-up.

[ginkof]

well you're still under warranty for 2k more miles... take it to the dealer and have them check it out for you. It could be a lot of stuff! If its wear and tear they probably wont cover it, but who knows! You might get lucky.. or atleast you'll get some useful information free of charge

[bagher]

what could it be? it's funny that the trip computer says my range is 350 miles on fill up but I'm getting closer to 250.

[Dan[FN]6262]

yeah, probably something to do with carbon build up on the intake valves. the FSI's do it because of how their PCV system are set up. but, this is only a guess. like said above, take it to the dealer and see what they say.

try seafoaming it thru the vacuum lines.

GL

[philaboy]

I used injection cleaner, had the problem when I got the car a few months ago! I get like 21 city- was getting like 14-15 city

[Dan[FN]6262]

I used injection cleaner, had the problem when I got the car a few months ago! I get like 21 city- was getting like 14-15 city

but that wouldnt have cleaned the intake valves because of how FSI works. only air passes over the intake valves on the FSI motors. the fuel is directly injected into the combustion chamber. seafoaming thru a vacuum line directly into the intake mani would allow it to wash over the valves and clean them.

[philaboy]

You are right, but it did help me!


Shank210;4045198']but that wouldnt have cleaned the intake valves because of how FSI works. only air passes over the intake valves on the FSI motors. the fuel is directly injected into the combustion chamber. seafoaming thru a vacuum line directly into the intake mani would allow it to wash over the valves and clean them.

[Dan[FN]6262]

lol im sorry, i wasnt insinuating that you were wrong in anyway!

[philaboy]

Ahhhhh no, it'z cool- Ino, but you are right[:)][:)][:)]


Shank210;4045241']lol im sorry, i wasnt insinuating that you were wrong in anyway!

[Dan[FN]6262]

OP, try running fuel injector cleaner and seafoaming it [up]

if you go to the dealer and get them to clean the intake system or whatever they call it, i think someone posted that it cost them like 300 bucks. something you could do for under 10!

[philaboy]

$300[o_o] I see they still like getting uz from behind[:D]



Shank210;4045291']OP, try running fuel injector cleaner and seafoaming it [up]

if you go to the dealer and get them to clean the intake system or whatever they call it, i think someone posted that it cost them like 300 bucks. something you could do for under 10!

[Dan[FN]6262]

$300[o_o] I see they still like getting uz from behind[:D]

the worst part is they dont warn or use lube [o_o]

[philaboy]

They need to start using lube, or my next car will be a BMW! I lie, I lov Audi, itz everything all my Vw's wanted to be[;)]


Shank210;4045625']the worst part is they dont warn or use lube [o_o]

[wayneB7]

bone stock, 48.xxx miles, mostly city driving, getting 15mpg. what could be the culprit?

Oxygen sensor, if the culprit is not your right foot. [:)]

Also, driving style viz smoothness (taking off and slowing) -- that hampers fuel economy of any car big time.

[bagher]

o2 sensor would trigger a CEL, no?

[marcink99]

I have same problem check it out at a dealer used fuel injector cleaner and nothing changed. Could somebody please do a seafoaming walkthrough with pictures?

[wayneB7]

o2 sensor would trigger a CEL, no?

I must confess, I don't know. Somehow I doubt it.

Here is information on my tip about O2 sensor (http://www.google.com/search?q=oxygen+sensor+fuel+economy&rls=com.microsoft:en-us:IE-SearchBox&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7GGIH_en).

[marcink99]

huh and how could we troubleshoot o2 sensors since dealers will always say there fine till you get check engine light

[MCT9891]

Don't have such a heavy foot... drive like a grandma and you get 23mpg city

[wayneB7]

huh and how could we troubleshoot o2 sensors since dealers will always say there fine till you get check engine light

Once everything else is eliminated, he would simply replace the O2 sensors. It is a consumable after all.

[marcink99]

hmmmm maybe we should unplug it get a check engine light go to dealer and get it replaced under warrenty. Where is this o2 sensor? How many is there just one?

[A42S4]

Have you had any engine lights pop on or off? I was having shitty gas milage but it turned out my fuel pressure sensor was bad.. Im seeing an improvement now.

[bagher]

Have you had any engine lights pop on or off? I was having shitty gas milage but it turned out my fuel pressure sensor was bad.. Im seeing an improvement now.

no lights on at all

I used BG44K on my last tank

[wayneB7]

hmmmm maybe we should unplug it get a check engine light go to dealer and get it replaced under warrenty. Where is this o2 sensor? How many is there just one?

There are two - front and rear - and they cost about $250 + taxes, S&H etc. (from genuineaudiparts.com).

I am not sure precisely where the location is.

[nnnick]

something is definitely wrong, my computer reads about about a 500 or 510 mile range when I first fill up, then after driving it, it will usually go up since I drive like such a grandma and am on freeways most of the time. And I generally average over 500 miles since last fill-up every time (again, mostly freeway, but still).

[Tanner]

I get about 380 miles per tank, mixed city/highway driving though more city than anything else. City driving is a killer on gas mileage, and it gets worse if your commute has a lot of stop and go vs one with very little stop and go. Mileage purely in the city, I think I'm getting in the 20-21 mpg which is reasonable.

Also what kind of fuel are you using? Any of it with ethanol? If you are using 91 with ethanol, switch to something else that doesn't use ethanol.

[illegitimus]

is there gasoline fuel that does not have ethanol these days?

[msharifi]

o2 sensor would trigger a CEL, no?

Not really... Do you have a VAG com? Mine didn't trigger a CEL but when I did used VAG Com it showed both of the 02 sensor bad. The first 02 sensor controls your air/fuel which your MPG can be poor..

[msharifi]

hmmmm maybe we should unplug it get a check engine light go to dealer and get it replaced under warrenty. Where is this o2 sensor? How many is there just one?

2 but the one before the CAT is the one that cause cause your MPG to go down.

[marcink99]

ok before when i used to fill up my car would show 480 till empty now when i fill up it shows 340 dealer checked my car claims evrything is ok recomended injection cleaning service for 200 i believe. I have 34k milles 06 2,0t recomendations? I ran injector cleaner couple times.