Why is my vx taking so much petrol?

[justagirl86]

I have a 2000 model VX commodore. I fill up at least twice a week if not more, and I am only driving locally..

I am sick of spending so much money..

Can some one please tell me what this is, everytime I see a mechanic, they take my money and say they have fixed the problem, only for it to still be the same

[DJP16]

How many km's do you roughly get from a tank? And what have the mechanics efforts been? Don't forget, a 3.8l v6 isn't going to give you the most amazing fuel economy..... :P

[Cameron P]

how much do you pay to fill it up(empty to full).. how many k's do you get out of it?? if you dont know use the trip meter to calculate it on your next tank

mines manual and i pay roughly $100-110 from empty to full

and if i baby it (rev to roughly 2500-300rpm eahc gear) i get around 700km's per tank. hope this helps

[2DIE]

Depends how you drive partly but my VT V6 feels like it uses twice as much fuel as my VN V6 did. If its auto that could be slipping and causing it to rev higher, check your air filter too, apparently you get better economy with a new filter than a old dirty one but I don't think it would be a massive difference. Have you ruled out any of the cylinders not getting spark or a bad injector?

Probably a lot of other things but that's all I can think of at the moment.

[justagirl86]

thanks for the replies, but I really don't know what most of your are talking about..

I found this forum while looking on google..

I fill the car at least twice a week, I put around $100 each time.. and the needle thing on the fule gage goes up and down all the time...

In one day, of driving say no more than a half hour away, and I don't do this every day, the gage goes down by a quater of the tank, then 2 days later it may jump back up.

We have told the few mechanics we have seen about theis problem, and all the say is they have fixed it.. My partner and I have no idea about cars, so we don't know if he does actually look at the problem or not..

[Cameron P]

if the gauge goes up and down randomly then its the fuel gauge sender?!?!?!

[justagirl86]

sorry, what does that mean ?

[2DIE]

Oh I see, sounds like a job for a auto electrician. Probably a fault in the wiring somewhere.

Better off taking it to a auto electrician yourself than taking it to a mechanic even if its just to have a chat and get a quote.

Or take it back to the ones who "fixed" it and tell them that they didn't fix the problem. If they say they wont fix it for free after already charging you ask for your money back as they didn't do what they charged you for.

[2DIE]

if the gauge goes up and down randomly then its the fuel gauge sender?!?!?!

Could be the sender or the gauge itself or anything between.

[justagirl86]

thanks guys

[Cameron P]

hmm but if she fills up a $100 a couple of days later then the gauge isnt reading wrong.. she is actually using alot of fuel..

does your car run rough or anything??

[Cameron P]

is there any leakages from under the car? like if you go to work one morning after the cars been sitting over night and see a pool of liquid???

[blacknight]

Could be other physical factors like low air pressure in all four tyres, wheels out of alignment, or you are carrying too much unnecessary junk in the car? a heavy car generally needs more power to push it? I eliminated the spare tyre cradle but retroffitted a fire extinguisher, a first aid kit, a basic tools box and an over night bag in the car. Travel light...

[soop]

if you're using 60ltrs of fuel ever few days I'd be looking for a puddle on the ground somewhere.

You don't live near bogans do you? (Stealing your fuel)

[blacknight]

damn...didnt think that someone might be siphoning off your fuel. seriously, the fuel flap on the VX is as much help as a lead parachute. its easy to open and get free go go juice. My friend's Nissan got siphoned this way too by some 'illegals' but a swift kick to the head (and some bruises later) scared them off

[justagirl86]

No, there is never a puddle anywhere. and I highly doubt anyone is stealing the petrol.. I park my car in front of 2 other cars..

I think it could be a factor of the wheel alignment, coz it pulls to the left alot, and maybe the tyre pressure.. but I don't understand how to put the air in the tyres without over doing it..

[coasty]

fill your car and reset the trip meter or write down the kilomters. when you refill it write the kilometers down again.
what you need to do is work out how many liters per 100 kilometers your doing. if you put in 80 liters and youve gone 700 kilometers you divide 80 by 7. this will give you 11.4 liters per 100 ks. if your in the city with lots a stop and start its not too bad depending on how you drive.

[Full Spectrum]

If i drive all local my av is poor at about 16-17 liters. combine and i can get about 10.8 - 12.5.

Do what others have said, check you don't have light fingers around your place. Check for dropping fuel. check error codes, check plugs filters. if you have done the fuel pump sender unit. head off to an auto elec. the full unit will be replaced as of VT II they changed the system. you will be looking at about $260 or so to replace the fuel pump. but still something like that might not be the issue if it's drinking to much fuel. so as above write down your km's travel and fuel used next time you fill up, and go from there.

[calais24/7]

Also if you have the standard wheels, i would be putting about 36psi into your tires, make sure they are cold when you do it though. By cold i mean dont drive it for a few hours and go to the closest servo. Use your trip computer to see how many kms you are getting each tank.

[DLFHUB666]

I thought i would throw another one in there o2 sensors could be fuged.

[graham7773]

Once more, I'm with soop. If you are sure you are filling up twice a week, look for a leak. Also, try to park so your filler is very close to something hard (another car?) If it is not a leak or theft, it is also not your crazy fuel gauge. That in itself will not make you use more fuel. When was the last time a service was done? IE oil + filter. Air filter, Fuel filter, Spark plugs (and leads?) Has a wheel alignment been done? (front and rear) As previously suggested, 36 psi in the tyres. (I run 40 in mine. Harder ride but better fuel economy) o2 sensors as DLFHUB666 said above. Transmission slippage would be fairly obvious if it is happening. Dirty fuel injectors can cause this also. To finish on a not so bright note, the problem can be a combination of any of the above. start with the simple things.

[Cameron P]

where abouts in sydney you live???? if you dont mind me asking.

i worked in the city for a couple of months.. so travelling from out west i was stuck in traffic for approx 2-4 hours a day... fuel econemy went through the roof and i was getting like 300-400 k's per tank. if you get less k's then that theres definetely a leak lol

[justagirl86]

I live in western sydney, and I never drive to the city.. I only drive my suburb or surrounding ones..

[Cameron P]

just saying that if your fuel economy is worse then that then its leaking hahaha

im from western sydney aswell. want me to come have a look?? doesnt bother me

[justagirl86]

hi, the partner is a little weiry with you coming to look at the car.. he doesn't mean it in a bad way haha

I am trying to sell it though, so if you know of anyone who wants it, let me know..