man i can get like close to 450 miles out of my full tank. in the summer. i can still almost squeeze out 400 in the winter and its like 15 degrees outside here.

 

have you done any mods or a recent tune-up lately? Are you light on the gas? How do you do it?

 

It would help to put like 0w30 in for winter but I don't know how much. I run 5w30 Castrol Syntec all year and I have been averaging 220-240 a tank in town generally filling up w/ 14.2 gallons or so. The summer I was getting more like 19 now its like 17 not that big a deal and I drive it hard about 33% of the time. I have new plugs, new wires, replaced a couple vacuum lines, new TB, drive belts, and drive belt tensioner. I know my plugs are NGK's w/ the 4 tips but not sure which that is since I didn't install them and got them w/ the car about 9k miles ago. Haven't even touched my MAF yet. Hit me up on AIM and I or some of the others I usually chat w/ on there can try n help a bit.

 

I'm halfway through the tank and the computer indicates that I have enough gas for 220 more miles. about two weeks ago when I had just purchased the car, the computer was indicating 55mpg, 65mpg, going outta wack. I managed to do just 180 miles with just about 3 quarters of the tank,so the second time I filled up with the car in my possession, I poured in one of those injector cleaners. It made a big difference. I get way better mileage now, after that cleaner got the job done. and it's crazy cold in NYC as well. oooh, it's a 1.8t, 2000 a4

 

Buy a universal pre cat oxygen sensor, don't burn gas with ethanol, and maybe a new MAF at advance if the oxy sensor doesn't fix it. Borrow the claw foot tool from your favorite parts store to change that sensor.

http://www.oxygensensors.com/

 

im gonna try n pull codes today and see if anything is up. car runs fine though. power is still the same.

 

I'd look further into that vacuum leak theory too. I wonder if a FPR vacuum hose springing a leak could cause a problem like this. But all the little ones behind the intake get old and crack. I replaced like half of them just cuz I was working back there.

 

a4Bam, what injector did u put in? Is it the stuff you get at like the bp? i would like to get some but tell me where to pick it up

 

Manual is even more fun in the snow. When you have a clutch, you can really let the RPMs fly and send the snow 6 or 7 feet in the air, its a blast.


To contribute to the thread though, I support that winter is worse on gas mileage for the physics of cold air. Correct me if I'm wrong but the purpose of a cold air intake is to get the colder, denser, more oxygen rich air so the computer will throw more fuel in the cylinders to increase power so is it so unreasonable to thing that the sub-zero air of winter isn't more oxygen rich thus allowing the engine to burn more fuel cuz its getting more oxygen? Not to mention the extended warming up wont help much either so yes, I'd say winter does have a fairly large impact on mileage.

As for the cone filter being better or worse, trey25's report that the stock airbox is sufficiently efficient is true. The cone filter will allow more airflow so the engine can breathe better and it sounds mean as hell and can give you a couple extra ponies, but for the same reason cold air negatively impacts fuel economy, with a cone filter, you're getting a lot more air with a lot more oxygen in it. IMO stock airbox with a K&N panel filter is sufficient enough. The filter will give a smoother airflow which is said to also boost HP and torque, but you still get the factory tuned amount of air so mileage isnt affected as heavily. But I'm a physics major, not an engineer so I may be wrong with that.

Lastly, to sidetrack the thread for a tiny blip: Trey25, is the honeycomb grille you have on your car cheaper than a Kamei mesh grille? If so, where can I pick one up? I've been wanting either a honeycomb or a Kamei for a while now, but the Kamei is a tad too far out of my budget so if the honeycomb one is cheaper, I'd love to get one. Thanks m8

Hope my 2 cents has helped a little,

-J

 

Also cold weather makes the oil thicker. You can actually feel the performance sometimes in the winter. Its by no means a full 10hp but its at least noticeable. Its different w/ turbo cars though. In some cases they run worse due to the tune.