Bad fuel economy/When should I be filling up?

[chrism182]

Hey,

I have a 2000 Manual VX S Pack V6 and I wanna get the most k's out of a tank that I can, as I have pretty crap fuel economy for a manual anyway. (450km a tank, tops)

What could be causing such bad fuel economy?

Also, when should I be filling my car up? I have got the needle down to about 2mm above the red line, but the fuel light doesn't go on. So to get the most out of a tank, when should I top up?

Cheers,
Chris.

[GMMAD]

stuffed 02's will coarse bad fuel economy

[holden-4-life]

dude thats not that bad fuel economy
in my VR auto b4 a few mods i was getting 330 from full tank to 1/4.
is that from all highway driving? coz then thats bad

shouldnt let ur fuel go that low coz u pick up all the crap from the bottom of ur fuel tank.

refill at the 1/4 mark

[Tom_1569]

What sort of driving are you doing?

I get around 450-500 all city/town driving, but out on the highway I've got 800km to 58 litres (75 Litre tank).

The fuel light comes on at 90km to go, but it could be at a certain level in which your driving style will means less. They also apparently keep 7 litres in reserve, but not 100% sure on this.

[VH commodore]

stuffed O2 sensors like said above, also a dirty air flow meter could cause poor fuel economy. also if u didnt know ecotecs have injector shut off when u are off the accelerator and have enough revs and speed etc. so slow down using the gears and u'll use no fuel, should be easy in a manual.

[Full Spectrum]

I think the reserve is way out with the VT's. I get about 450-500km. Red light has been on for a good 50km. Go off and fill the car with 55 litres of fuel. That's a staggering 20 litres left, And all the car is showing is 20km to go low.

[chrism182]

What sort of driving are you doing?

I get around 450-500 all city/town driving, but out on the highway I've got 800km to 58 litres (75 Litre tank).

The fuel light comes on at 90km to go, but it could be at a certain level in which your driving style will means less. They also apparently keep 7 litres in reserve, but not 100% sure on this.

Hey mate I'm actually also around the East Gippsland area so you'll know the roads. Mostly a mixture of both, probably 70% town, 30% highway driving for me.

[Tom_1569]

Hey mate I'm actually also around the East Gippsland area so you'll know the roads. Mostly a mixture of both, probably 70% town, 30% highway driving for me.

Oh cool, What part of East Gippsland? Also see the link in my sig, register your interest if your interested.

Fuel economy probably isnt to bad if its mostly town driving depending on how hard you drive to.

[danja]

stuffed O2 sensors like said above, also a dirty air flow meter could cause poor fuel economy. also if u didnt know ecotecs have injector shut off when u are off the accelerator and have enough revs and speed etc. so slow down using the gears and u'll use no fuel, should be easy in a manual.

I think the reserve is way out with the VT's. I get about 450-500km. Red light has been on for a good 50km. Go off and fill the car with 55 litres of fuel. That's a staggering 20 litres left, And all the car is showing is 20km to go low.

What these guys say is true. New O2 sensors, clean your MAF, that should see a substantial economy and drivability improvement.

When talking about your economy, its more helpful to speak in L/100km, because like SlickHolden says, the reserve on these cars is about 15-20L.

I used to have a manual VT V6, I'd do the daily commute to work and back in Sydney traffic (on Victoria Rd for those who know what a shocker it is) and I'd get 12.5L/100 consistently. If I did less peak hour driving it would nudge under 12L/100, but was always around that mark.

The best time to refuel is when the petrol is cheapest! Where I am thats usually Wednesday morning. If you can survive by only refueling once a week, do it when its the cheapest. If you drive so much that you need to fill mid-week, try and do it as soon as the fuel light comes on.

[chrism182]

Oh cool, What part of East Gippsland? Also see the link in my sig, register your interest if your interested.

Fuel economy probably isnt to bad if its mostly town driving depending on how hard you drive to.

I'm down near the Bairnsdale area.


I mostly do town driving so I'll see how many litres I get out of a tank when i do a bit more highway driving and see how I go.

[camo645]

yeah.. im having the same trouble with mine, but im getting bout 350 out of a tank..but i drive hard =P i know that the VX has a 60L tank i think.. but whenever i fill up when empty i can put in about 45.. and thats about it. am i doing something wrong? or just crazy?

[kaishiz]

I can not believe it... i went to Mt buller on the weekend and my car did 8.3/100kms. i was a feather foot all the way there and going about 110 in 5th but very slow acceleration to get up to the speed. best i have ever done with this car.

[glowworm]

Last week i drove Brisbane to Melbourne ,Fuel price ranged from 1.08 ltr to 1.19 to 1.25ltr i did 8.1/100 kms in an auto V6 sitting on an average speed of 110 kms hour I did put new O2 sensors in 6 months ago and did buy a new MAF meter in about 9 months ago i also run a AIR HOG reusable air cleaner which is 3 years old just before the trip i cleaned the AIR HOG end result i was happy with my kms/100 ...

[mofo sixx]

driving habits

[Jesterarts]

VX's are a funny car...

Because each fuel guage is electronically calibrated... there might be slight differences in how much fuel is left in regards to what the fuel guage says.

I used to fill up when the needed was in the red... and usually i would have 10L in there still left...

What you want to avoid is running it dry or close to because the fuelpump in the tank doesn't take kindly to this.

Just next time you fill up, see where the guage is... then see how much you fill up... and go from there.

I know that the sweet spot to getting a VX running after running it completely dry... like... run out of fuel on the side of the road, it about 10-13 litre... So if you keep about that much in the tank at all times you should be sweet.

In regards to your economy... damn!!! Get it tested to see if it's running rich... and it will probably be the 02 sensor, or the MAF... or the air temp sensor...

I used to get about 490km out of a tank giving it a good trashing(with full exhaust and intake)... and 430km per tank thrashing it once i had the 3.73 gears in the diff.

Good luck mate.

[chrism182]

When I fill up is the Fuel guage supposed to sit directly on F? Cause when I fill up its about halfway between 3/4 and 4/4

[danja]

When I fill up is the Fuel guage supposed to sit directly on F? Cause when I fill up its about halfway between 3/4 and 4/4

It should sit on "F". Sounds like you calibration is out, might want to get it recalibrated.

[Tom_1569]

I can not believe it... i went to Mt buller on the weekend and my car did 8.3/100kms. i was a feather foot all the way there and going about 110 in 5th but very slow acceleration to get up to the speed. best i have ever done with this car.

I got 7.81L/100Km/h, going by how many K's I did to how much fuel went back in. It was From Sale driving around town for the day, the next day to Bendigo via The City, driving around Bendigo for two days, and home via melbourne with Peak hour and around sale the next day, not bad I recon. On the highway I would be suprised to see figures in the 6 range. I've also noticed I get better fuel economy to BP Petrol then other servos using 91 at both. And I get better fuel economy sitting just above 2000rpm at cruise, instead of just below it.

When I fill up is the Fuel guage supposed to sit directly on F? Cause when I fill up its about halfway between 3/4 and 4/4

Either your gauge or sender is up shit creek, or a breather hose is blocked and its not filling up all the way.

[VH commodore]

I can not believe it... i went to Mt buller on the weekend and my car did 8.3/100kms. i was a feather foot all the way there and going about 110 in 5th but very slow acceleration to get up to the speed. best i have ever done with this car.

when i did i drive from brisbane to newcastle and back i was getting 8.2L/100k's that was without driving with fuel economy in mind overtaking at every chance, aircon on stereo on in the wet for about half the trip, and my O2 sensors are original and my cars got 180 000 on it lol...2 wire o2 sensors are ment to be changed every 80 000k's so might do that soon

[Jesterarts]

Yeah, as people have said it should go all the way upto 'F'.

Go into holden and you can get you're fuel guage re-calibrated by them.. cost me about 25 bucks when they did mine. Because mine was reading that it was just in the red but was sputtering to a halt on the side of a freeway.

If that doesn't do it... the sender could be on the way out... and they are a touch pricey as the sender and fuelpump are one unit or something like that... can't remember the exact details, but i do recall there is a catch.

Good luck mate.

[kaishiz]

I had a full car too.... snowboards three peeps and weighin 90+ each.... i rekon if i roll solo i reckon the car could reach in the 7 ltrs....

[chrism182]

Took her to a mechanic today. Said the MAF was blocked up with grass so hopefully I will see some improvement.

[VH commodore]

Took her to a mechanic today. Said the MAF was blocked up with grass so hopefully I will see some improvement.

ha yup that would do it...big time

[VXSSComm]

In my VXSS my fuel pump was re-called so that could be why your fuel consumptions is bad. I noticed after it was replaced my fuel consumption has been better. Since I bought the car (Brand new) I have kept a fuel log. I only buy Mobile Synergy 8000. I do a lot of freeway driving. I average around 350Ks per tank. I fill up every eight days.

[Mick1988]

Using the engineers mode on my VX I've cruised at around 70kmh getting 4.1 l/h

So if I convert to liters per 100km

4.1 / 7 X 10 = 5.85 l/100km

That's pretty decent for a 7 year old V6. Obviously I don't always get this economy because I do a fair bit of stop start driving. I also sometimes don't drive my car all week, just move it in and out of the driveway every day (and starting uses a bit of fuel). I still get 420-550km per tank depending how much freeway/highway driving I do.