Ok so I filled up my tank and drove 16 miles back home. When I got home the gas gauge was more than halfway to a quarter tank. I kept it under 4k the whole way usually at 2k or under. Any ideas as to why my mileage is so shitty? My last tank i averaged 17mpg.

 

Tune-up time?

 

Yea I hope... I just got in Bosch universal O2 sensor, NGK plugs and wires and a Fram fuel filter. The oil was just changed. Right now Im using 5w-30 with it being anywhere between 0-35 degrees here in Ohio. Anything Im forgetting tune up wise?