17.5 Litres per 100km

[anarklov3r]

Hey guys, I should probably post in the "What millage should i be getting" thread, but I've decided not to hi jack it

What ive done is i filled up the tank to 100%, reset ODO, let the ODO hit 100kms (was actually 96kms), and then topped back up to 100%.

The car chewed up 17.5 litres for 96 kms travel distance (up and back to uni, 12.5km to get there, 6 of which is freeway, then 4-5 traffic lights over the rest of the distance)

Looking up the specs of the Holden VP's i should be getting around 8lt/100km free way and 12lt/100km city driving, and since i do half half, id assume i should have got somewhere in the 10 - 11 litres / 100km

Ive changed the coolant sensors (car was running cold all the time) and put in a new thermostat, and also new spark plugs. Only thing left is a new O2 sensor.

What do you guys think?

[88GreenVN]

Bad ecconomy from a VP is not uncommon. To fix may take a few bits to fix.

1 have all the feul system in good order like filter and injector cleaner. Check the o2 sensor as this may be reading the car is lean and adding fuel that is not needed.

Also you could try a new memcal tune that has a better fuel map in it. Dont know much about the re programming memcals - but from the one's I've had done for the VN 6's - well worth the money. My VN wagon went from using 16/17 L/100 back down to 10.6L/100 kms.

[vnv8driver]

Thats about average for a v6 if you put the foot down !

[FrangaVP]

Well the general rule of thumb is that the holden figures are bull**** along with all the manufacturers fuel consumption figures, people in the know I have talked to about say you should generally add about 10% on top of the factory figures. As for your car, how many km's has your motor done? Personally my VP Berlina Wagon has done 330k kms and it still gets 15.5L/100km and thats all city driving no freeway. Have you changed your Air Filter perhaps that is contributing to the problem, Also a loss in exhaust back pressure may also be partly responsible if you've got a hole in the exhaust system somewhere.

[vnv8driver]

There not bull**** if you drive it the way it was intended to and the motor/electrics are in good order, my 18 year old v8 averages 15.00 litres around town (after cutting out all the bull**** this is the correct milage) and its exactly what holden said when they were released 15 odd years ago.

[FrangaVP]

Yeah but what you have to remember is no one drives the way they intend them too and plus the vast majority of that testing is done on a either a track or indoors on a rolling road without any wind resistance or changes in road surface. I have heard of cars getting the factory figures in fuel consumption but only after modifications or running high octane fuel. But hey man if you can get the stock figures the more power too ya, I wish I could do it would certainly help my light wallet.

[vnv8driver]

that was something i did notice, and i would of agreed with you a few weeks ao, its been these past 2 weeks that ive looked at the trip metre and it says 15.00 which was the exact amount that holden quoted.... you also hear of v6 commodore's doing 6.5 litres per hundred kays under normal driving conditions, thats one that hasnt been proven and im a little skeptical about.

All im saying is i drive my car normally, and ver a distance around town and got the holden quoted figure, then you get other readings off the trip meter that are either really low or really high, which just means that a proper reading hasnt been recorded or like you said, you just put the foot down.

[88GreenVN]

The 88wagon on the expressway (at 100kph) - it can drop into the 6 to 7 L/100 kms. Greefoam tune for the win

The V8 on the expressway sits at about 10 to 11 L/100kms. Again Greenfoam tune for the win

[FrangaVP]

that was something i did notice, and i would of agreed with you a few weeks ao, its been these past 2 weeks that ive looked at the trip metre and it says 15.00 which was the exact amount that holden quoted.... you also hear of v6 commodore's doing 6.5 litres per hundred kays under normal driving conditions, thats one that hasnt been proven and im a little skeptical about.

All im saying is i drive my car normally, and ver a distance around town and got the holden quoted figure, then you get other readings off the trip meter that are either really low or really high, which just means that a proper reading hasnt been recorded or like you said, you just put the foot down.

Have you done anything to your car to improve fuel economy or have you just maintained the motor really well? I wish I could get such good figures on my 6 let alone an 8.

[vnv8driver]

i dont doubt that in any way but ive also witnessed mine that low and even lower on the big downhills. Ive gotten low readings of 8.x??? on the highway out of my calais but it wasnt correct. Its only after ive left the trip for a while, driven normally that ive noticed the figure on the dash is exactly as quoted by holden...

I used to reset mine every week at fillup (whole reset not just km's travelled) and got ether really low or really high readings

[88GreenVN]

that was something i did notice, and i would of agreed with you a few weeks ao, its been these past 2 weeks that ive looked at the trip metre and it says 15.00 which was the exact amount that holden quoted.... you also hear of v6 commodore's doing 6.5 litres per hundred kays under normal driving conditions, thats one that hasnt been proven and im a little skeptical about.

All im saying is i drive my car normally, and ver a distance around town and got the holden quoted figure, then you get other readings off the trip meter that are either really low or really high, which just means that a proper reading hasnt been recorded or like you said, you just put the foot down.

I have calibrated the trip computers in 2 of the VN's (88 & 91) and get very good numbers like when I put 50 L in the trip computer is within 1/2 litre.

The 89 sedan on the other hand is still saying 14.5 L/100 but is only taking 35L to fill so I'll need to set that one better I think. It has the same tune as the wagon so should return close to the same. The driver has not taken a record of litres used when filling it up so I cant do any calibrating for her - it can wait until after her year 12 exams.

Anyway with a greenfoam tune you can and will get better ecconomy.

[vnv8driver]

Have you done anything to your car to improve fuel economy or have you just maintained the motor really well? I wish I could get such good figures on my 6 let alone an 8.

its got a tune and cai and been looked after. i also fill up with premium..

the economy didnt really drop at all after the tune as i thought at first, and ive also been driving like any 'normal' person would which is about 1 cm throttle.. id expect it to be around the same at light load conditions but to chew more on the highway.

[vnv8driver]

I have calibrated the trip computers in 2 of the VN's (88 & 91) and get very good numbers like when I put 50 L in the trip computer is within 1/2 litre.

The 89 sedan on the other hand is still saying 14.5 L/100 but is only taking 35L to fill so I'll need to set that one better I think. It has the same tune as the wagon so should return close to the same. The driver has not taken a record of litres used when filling it up so I cant do any calibrating for her - it can wait until after her year 12 exams.

Anyway with a greenfoam tune you can and will get better ecconomy.

i havent gone to the trouble of fiddling with the cal settings, its just stock 625 at the moment... i found this car (versus my vq v8) uses more fuel, both had same cal settings but this car seems to be far more accurate at determining how much fuel is left and how many km's are left...

The vq gave spastic readings (lower) most of the time which i never pinpointed.. Ive come to this conclusion after i stopped resetting the thing every week and just let it ride. Who knows if what im saying is the bald truth but its what i see in the car and im a big believer of seeing is believing.

[88GreenVN]

The fuel flow rate (stock 625) this is the amount of feul being used by the car.

So when you have used 40 Lt (via trip computer) and the feul remaining = 23 Lt and your fill up = 41Lt you adjust the flow rate so that next time you fill up it is closer to the actual fuel used.

So first you get the amount remaining in the tank set - then you do flow rate.

Also you do a manual calculation too - old school pad n paper and double check the numbers.

This info on calibration is in the hand book too.

[Nevyn]

The fuel flow rate (stock 625) this is the amount of feul being used by the car.

So when you have used 40 Lt (via trip computer) and the feul remaining = 23 Lt and your fill up = 41Lt you adjust the flow rate so that next time you fill up it is closer to the actual fuel used.

So first you get the amount remaining in the tank set - then you do flow rate.

Also you do a manual calculation too - old school pad n paper and double check the numbers.

This info on calibration is in the hand book too.

I keep a pad and pen in my car, so every time I fill up, or even just add $20, I write everything down from the L3 cluster. After 6 mths I'll add it all up to get an accurate reading on the mileage I'm getting.....I do a hell of a lot of k's on the freeway with about 1/4-1/3 of more of that around town.

[Nevyn]

The fuel flow rate (stock 625) this is the amount of feul being used by the car.

So when you have used 40 Lt (via trip computer) and the feul remaining = 23 Lt and your fill up = 41Lt you adjust the flow rate so that next time you fill up it is closer to the actual fuel used.

So first you get the amount remaining in the tank set - then you do flow rate.

Also you do a manual calculation too - old school pad n paper and double check the numbers.

This info on calibration is in the hand book too.

how do you adjust the flow rate? that sounds interesting

[88GreenVN]

how do you adjust the flow rate? that sounds interesting

Hold the reset button for 3 secs. Then use the + or - while still holding the reset.

Mine is set to 629 on the V8.

Each car will be different. If you max out the settings you can get very very good or very bad economy by just changing the numbers.

But you must have the feul remaining set correctly before changing the flow rate.

[greenfoam]

The fuel pressure regulator allways has to be the primary suspect in bad fuel consumption, the O2 sensor a little and that's about it, everything else is just a couple few percent here and there, unless you have an injector that has just had a massive failure and is stuck on all the time

[vnv8driver]

ive never taken the time to calibrate my dash but im going to look into it 88. ive seen the how-to's around but never had a squizz at how its done, it would be good to see an accurate figure for both the v6 and v8 and set some mysteries straight.

[anarklov3r]

The original VN motor blew a head gasket and was totally stuffed. It was replaced with the VP which had done 130,000 at the time, and its around 180,000kms now The chassis just hit 204,000 kms. its still fairly unused considering its age.

I dont really drive lead footed.. car hardly ever reaches 3,000rpm (thats when im entering a motorway) 2,000 - 2,200 ish is as much as ill push the pedal down.

[ucwepn]

do you have mags ? I have a feeling my 18's are giving an incorrect odometer reading because the overall diameter is bigger the wheel turns less than a 15 inch wheel would for the same revolution. so my figures of around 350km a tank are prolly more km's than what odo says. Anyone with rims noticing anything similar or am i losing it LOL? Anyone had their speedo calibrated correctly for their rim size?

[88GreenVN]

do you have mags ? I have a feeling my 18's are giving an incorrect odometer reading because the overall diameter is bigger the wheel turns less than a 15 inch wheel would for the same revolution. so my figures of around 350km a tank are prolly more km's than what odo says. Anyone with rims noticing anything similar or am i losing it LOL? Anyone had their speedo calibrated correctly for their rim size?

You can set the L3 dash by changing the 625 factory setting. Nudge it up or down and then check the readings between road markes.

[anarklov3r]

no mags, standard wheels Im probably going to change the O2 sensor over the weekend. Also change / clean all the filters in the car. And also throw in a fuel injection system cleaner.

[88GreenVN]

The fuel pressure regulator allways has to be the primary suspect in bad fuel consumption, the O2 sensor a little and that's about it, everything else is just a couple few percent here and there, unless you have an injector that has just had a massive failure and is stuck on all the time

In diag mode on the L3 cluster - is the flow rate in the middle screen connected to the fuel regulator at all?

In that screen the flow rate is Litres per hour @ idle and the normal amount was 1.5 or something like that.

[The Darkness]

definately replace fuel pressure regulator and oxy sensor. last week i got 210ish kms to a full tank, replaced them two and this week i got 380ish kms to a tank. well worth it in my opinion