Gas mileage decreasing!!
 

Hi, this is my first post amongst this forum and I look forward to much more discussion and learning here.

But first on my agenda, dealing with my cars decreasing gas mileage.

When I first purchased my 07 sport (2.3, 5spd) in 2011 with 70000 kms, I was able to get, 550-600 kms per tank (light comes on) in mixed driving mostly city, and 750 almost 800 on the highway. I was never delicate on the throttle but not flat footing everywhere i went.

At the start of the winter months, I noticed my mileage started dropping quite rapidly, guessed that some of the issue was that i was letting the car warm up in the morning and that the slower winter driving in stop n go traffic was taking a toll. Now the snow has gone and im still seeing this lower fuel mileage . Only lucky to get 500 kms on the highway being very conservative with the gas.

Car now has 107,000kms on it and I am just looking for some answers in to why it has dropped so greatly.

Some people have said that it is a fuel filter issue, or something with my injectors.

Help me please!!

Is the car running okay? Is the check engine light on? If anything is bad like a sensor that would cause a big drop in mileage it should cause the CEL to come on. If you're not seeing a CEL I'd start with a good tune up. You have enough km's on it now that it could be your pre cat O2 sensor has degraded and is causing the mileage to slip some but I wouldn't think as much as you are saying.

I get 350-400 miles per tank (til the low fuel light) (560km - 640km) and with just ove 72k miles on it (116km) it's still very consistent. I have not changed my air filter since it's not dirty enough to bother changing. I have also not changed any of the fuel or exhaust parts, sensors etc...

I think a plugged fuel filter or injectors would cause loss of power rather than excessive fuel usage. I think the air filter would do the same thing, just poor performance (since there's a pressure sensor to determine actual air intake).

Check the car out, like maybe ran over something to dent the exhaust, did some engine work & used silicone that could kill the O2 sensor, or cleaned some sensor with the improper chemical.

Do try a battery reset, I know my first tank is very high mileage after that since it's relearning the engine parameters & yours may have gotten screwed up.
You can also look at the throttle body, it's probably carboned up a bit & could use a cleaning. I don't think this would cause much change, but it's a good way to get poking around the engine to see if something looks out of place.
If nothing looks wrong, see if the check engine light comes on soon.

Never let your ligth go up !
 

Never let your ligth go up !

It's not good for the fuel pump, it pump's from the bottom so a good quantity of gas keep's a better pressure and sucking the bottom residue is not grest either!

Keep it always higher than 1/4! that's your ligth!;)

If your brakes are dragging a bit, that can kill mileage. After a drive, hold your hand at the wheel. If you feel much heat radiating off the disks, you've got a seized caliper or piston or other issue.