Using more petrol? Unknown reason :( Options

[Liam_c]

Hey everyone

Lately my car has been using more petrol than what it usually would, and i have no idea why.

When i bought the car, i was running it on 91 octane, and it was using about 8.5 L per 100km, and then about 2 months ago i upgraded to 95 octane and it was using 8.1L per 100km. No mater how i drove it on 95, it was doing high kms every tank i was loving it

But recently, its jumped back up to 8.5L per 100kms, and even though im driving it nicely, its still using alot of petrol. I started to notice it shortly after i had taken it on a car club run about a month ago ( driving around the hills, giving it a bit of stonk in the hills)

To some of you, this may not really be a problem, but its worrying me as i don't want it to get worse (and on my current run, it seems to be getting worse )

Where would be a good place to start looking for what could be causing this issue? I'm 90% sure it isn't a leak, as there is no noticeable marks on the ground after being parked up.

Air filter? Catalytic converter? Wrong fuel type? Fuel filter? O2 sensor?

Thanks

Engines a 3sfe.

[rentaspace]

Follow the guide on here for resetting the ECU, when I first got my car I was using 12-15L/100km, after I followed the reset guide it dropped to 11.3L/100km.

Then as box said, change fuel filter, ignition leads and spark plugs. While I was at it, I also changed my oil, oil filter and radiator fluid.
I am now using 9-9.5L/100km after these changes



EDIT:
I also use 95, but sometimes (probably once quarterly) I will use e10 to clean the inside of the tank out
When I do the e10 run I ise 12L/100km... Terrible...

The one time I used 98, I got 8.4L/100km

This post has been edited by rentaspace: Oct 8, 2013 - 6:57 AM