02Audi-A4-3.0

Sup all? I have an 02 a4 3.0L V6 with 84,000 miles on it. I have had the car for about 8 or 9 months. I had some work done to it before I bought the car and it was getting great fuel economy after the 2 new catalytic converters. I would get about 18 city and 26 highway. Since then I have only purchased an oil change (5w-30 Mobil 1 from audi dealer) I think that it had 10w-30 before I puchased the car. I figured that the lower weight oil would help with gas milage and winter conditions. However I now get 14 miles in the city and about 22 on the highway. Do I need a new pollen air filter or cabin air filter? Could this be an exhaust problem? I really want to put my finger on it and fix it before something bad happens. Thankyou all for the replies. If anymore information is needed please let me know... THANKS!

Espritman99

I assume this is your first winter with it? I don't know exactly how cold it gets in Tennessee, but where I am located gas mileage goes down significantly during the winter months due to our extreme cold. I run 0w40 synthetic in the winter.

02Audi-A4-3.0

nice to know. It has been about 20 deg. here. Thanks a lot man. ill see how it gets after a K&N filter

wanthema

it wouldnt matter if u got an kn filter or not, the difference between OEM filter and kn filter is you can reuse the kn filter again whereas the OEM one you have to replace after 40k.

gas mileage also goes down because of the amount of snow/friction from it and also because the heat you need to stay warm in the car when u turn your heater on, which uses lot of gas to operate.