fuel

[SaGe]

hey all,

ive been experiencing bad fuel economy lately like 300kms out of a full tank.
flashed the fault codes and only got code 12 normal operation.
is it possible that the O2 sensors are stuffed and it isnt showing up on the fault codes.

 

[kopper69]

There are many things you can do to improve fuel economy, O2 sensors are probably the most costly. Start off with the cheapest checks and then work your way up to the more expensive ones. Do a service on her first. Oil, coolant, filters, trans etc. Then do a search on this site because we have gone through good fuel economy checks.

 

[POVRTY]

yup what he said. check air filter. and take off your lead shoes. lol.

 

[digisol]

Seems there are vastly different driving styles, two blokes in the same car will get different results, drive the good bear way as per the book, gentle acceleration, predict the green lights and back off, don't speed etc.

My Vs wagon gets around 450kms around town but over 600 on the highway if driven at 95, then again drive at 105 or 110 and you can cut that 600 by 1/3, and your back to worse than city driving consumption.

300 a tank is not real flash, do some tuning, and then change habits, you may think your driving slowly, someone else may not, drive as if your a paid chauffer and someone in the back is having a scotch, don't spill their drink!

Smooth driving.

 

[Harvs82]

As others have mentioned, check the air filter, make sure its not dirty, check your plugs, make sure they are the right gap, maybe replace your fuel filter if it is clogged up or due for service (every 40,000km replacement for VS) and if you are still having troubles after that, perhaps get the injectors cleaned, and maybe the 02 sensors replaced. Another sensor to look at is the coolant temperature sensor, if this isn't reading correctly, the ECU will think the engine is running cold, and run a richer fuel mix.... giving poor fuel consumption.

I usually get between 360-450km out of a full tank of fuel in my VS V6, running on 95 RON premium unleaded. As a few other people have mentioned, the consumption can be easily changed with how heavy you are on the go pedal, and the varying traffic conditions.

Worst economy I have had out of mine is 24.5 litres per 100kms, when i used 7.5 litres to travel just under 30kms, which took nearly 2.75 hours because the Monash freeway was closed due to an accident....

 

[SaGe]

i hav serviced it recently simply because it needed a service and i hoped it would fix the fuel economy as a bonus however it didnt, for the past month i havent push the pedal to the floor or dropped the clutch, i dont even let the rpms reach 3000 and when its cold i shift b4 2000rpm.

i still get 300kms out of a tank.

i know wat to look for with bad fuel effiency. my question was can any of the sensors be stuffed and wont show in the fault codes cos i only get code 12. i dont want to change the O2 sensors if theyre still good.

 

[Harvs82]

i hav serviced it recently simply because it needed a service and i hoped it would fix the fuel economy as a bonus however it didnt, for the past month i havent push the pedal to the floor or dropped the clutch, i dont even let the rpms reach 3000 and when its cold i shift b4 2000rpm.

i still get 300kms out of a tank.

i know wat to look for with bad fuel effiency. my question was can any of the sensors be stuffed and wont show in the fault codes cos i only get code 12. i dont want to change the O2 sensors if theyre still good.

Yes the sensors can become 'Lazy' and not bring up any fault codes, but still not work properly. Your best bet is to take it to someone with EFI Live or similar, where they can monitor the oxygen sensors, and see if the voltage is changing rapidly, which it is meant to do from memory.

 

[SaGe]

thanx that was i needed 2 know