I have a 2006 Scion tC, 120k miles automatic. I just bought it a month ago., the previous owner was a mechanic and he did all the maintenance which I double checked. New oil, fluids, new spark plugs, air filters etc. Well I have been driving it and haven't had any issues, it runs great besides from the fact that it gets horrendous gas mileage. I've only driven about 50 miles and its already burned through almost a third of the tank. I would guess its getting 180 on the entire tank. I only drive around 1.5 miles to work on residential roads, 25-35mph. Even though its somewhat stop-go I feel that the gas mileage is still really off. I already got cleaner and cleaned the MAF sensor, still nothing. Air filters are good. No obd2 codes either, live data seems okay. At idle - SHRTFT1 - .8%, LONGFT1 3.1%. MAF ~2.95g/s. O2S12 0.800V, SHRTFT12 99.2%. Any ideas on what else I can try?
Well, it could be dragging brakes, but more likely you have a less than accurate gas gauge (I had a Camry that would get 250 miles on the first half tank, then 75 on the second half. Set your trip odometer and run the MPG when you fill up each time.
The other thing to keep in mind is that 1.5 mile trips in traffic yield the worst gas mileage of any type of driving - what kind of mileage were you getting in previous cars?
The car isn't even getting up to operating temps. 1.5 miles, that's an extremely short drive. Unless you're driving a hybrid, you'll get lousy gas mileage. Fill it up and go for a long trip on the highway (about 30 minutes each way), and see what mpg's you get. It'll probably be what you'd expect.
Clogged fuel injectors possibly?
Ill try running some seafoam through it to clean the fuel injectors, it might be the gas gage being off so Ill check it at the gas station.