The ultimate VR/VS fuel usage research page

bear in mind as your tank is at 1/2 way or below you will use MORE fuel because of the fuel system configuration.

A RETURN fuel system pumps unused fuel back to the tank, this fuel is heated because it has passed through the hot fuel rail and cooled the injectors, therefore soaking up heat.

Everyone knows hotter fuel=less power=more volume of fuel and because there is less fuel in the tank than a full tank more heat will be retained rather than dispersing through a full tank of fuel.

Once a VS series 1 utility gets to half way there is only bout 20litres left in the tank.

 

That's probably because I've enjoyed the performance boost The last figures at 7.5 Km/l was running up and down the Bruce Highway in the rain, with the aircon on. This weeks effort which I'll probably post in a day or two (filling tomorrow but it shouldn't take much I hope) was basically all stop start driving. (I still tend to 'floor it' if I have half a chance )


Tomorrow I'm taking a run with two adults (including me) & two kids in the car up the coast again, maybe coming back in the night or the next day. It's only about 250Kms, so I'll check what a fill is then.

Hey Digisol, I asked a couple of people in the auto trade and they reckon that ULP & PULP will mix in time. The general consensus was about three full tanks. I'm nearing that soon. I'm putting extractors and CAI in the next month or so, then I'll have a decent tune. Hopefully I might see a reasonable difference after.

 

Long Term Figures!

My car:

1997 VS Series 2 Executive
3.8 L V6
Manual transmission
Aircon
IRS
ABS
Dual IRS
Trip computer (3 window dash)

Distance 127,140.5 Km
Fuel 12,537.9 L
Consumption 9.86 L/100 Km

Best 6.89 L/100 Km (737.3 Km for 50.83 L)

Worst 12.91 L/100 Km (317.7 KM for 41.01L)

 

Michelson4301, Only once did I have fuel heating problems and that was the fuel literally boiling in the tank due to a very high road temp and a lowered vehicle + very hot weather, it would eventually stall the 500 Holley on the worked HT "not a commodore" as fuel being supplied to the pump was no longer a liquid, just bubbles so essentially it ran out of fuel.

Parked off the road for 10 min and away it went NP.

It's fairly rare but that was way in the bush 800+kms from the coast and 45 deg in the shade easy, the constant high speed driving simply boiled the fuel which could be heard bubbling via the filler cap once removed.

While not recomended it is possible to put pertrol on an electric stove and boil it, not recomended as a party trick as the flash point increases to a rather dangerous level, Kiddies, don't EVER try it at home.

I have a guess your float if not set correctly, I know several that have utes and fuel gauge levels are no different to mine or any other commodore so it's not a ute problem.

A "cool can" is a fairly simple thing to make, no rocket science is needed, merely a coil of alloy tubing about 2m long if straightened with decent in/out fuel line connections in a container of around 4 litres and the can is simply filled with both dry ice or plain ice in a brine for short distances, while an old trick now it's still legally used in some american racing, that can be done on any car and all will show a power increase to some degree always.

If put in the right spot dry ice will last several hours, more than most race distances, generally used with methanol but petrol benefits just the same.

Kwumley that statement came not from me but the fuel guru at CQ fuels, IE a lab tech at the company, I'm just an engineer I know jack all those years at Uni were wasted.

Quicker to drain the tank and have some PULP on hand so your fuel pump is always covered, but that may be too easy.

 

VR
V6
statesman
Automatic Transmission
Sedan
CAI (Cold Air Intake)
exhaust standard 2 1/4 inch
17'' vr clubbys
How often you stop and start as an estimated percentage 40%
How long your car sits idling 30%
How much excess luggage do you take in your car 20kg
How many people are in your car on average including you, 1/2
Where was the petrol purchased from (Especially when using premium) local no name servo
Average speed you think you do on a normal tank...says 47km
Number of kilometres your car has travelled....300000
How hard do you normally go on a take off (when starting from lights etc), pretty hard
How big your fuel tank is 80L
Getting about 13l/100km, think theres something amiss tho

 

Digisol I was merely trying to bring the point of fuel usage that people that fill up at 1/2 a tank and people that run the tank dry(or nearly) will have a higher L/100km than people that fill up at 1/2 tank or more due to the fuel heat soak.

I know this doesn't apply to this thread really but later model Gen 3's(I think with Fly by wire models) have a non-return fuel system and naturally higher fuel pressure so do not have the chance of heating the fuel in the tank like VR/VS models do.

 

im must be retarded because i cant edit my old post....
anyway, my results for week two are:
360k's from 38L...558.9k's a tank....10.5L/100k's

also, my week one results are wrong (yeah,i stuffed up)
they should be:
320k's from 35L...539.4k's a tank...10.9L/100k's

i did a trans service and oil and filter change yesterday...should be interesting to see any difference in next weeks results.

week three:330k's from 35L...556.2k's a tank...9.4L/100k's
which was a bit surprising as i gave her a pretty hard time this week...i had to see how good the newly serviced trans felt when i put the foot down,lol.

 

I can't edit mine either....

but running on Shell Optimax - 15.4 L/100km same driving style as before

 

Hi guys, I got a '95 VS and its done 213k.Fuel consumption has always been good and all I do to to keep that is maintain the thing....ie oil change (and use a GOOD oil it does make a difference) filter change,plugs and fuel filter etc. I did a trip recently and for 610km's averaging 110kph I used 50Lts. Surprised some...but not me...thats just what it does when its looked after. Who needs a jappa aye.? :hit:

 

On 9.65 l per 100 km.

Have ordered a CAI and a red line filter. Put on after a weekend away coming up the following week end. After that should have a definitive figure for consumption of this recently acquired wagon.

Anyone reckon I should put one on at time to see what difference either makes if any? That sentence may not have made sense but I know what I meant.

 

Yeah might be a good idea....Id be interested to know what difference a CAI makes

 

I'll do the CAI first. Over the course of six weeks or so I'll post any difference in guzzling rate from no CAI or redline filter to CAI without red line to CAI with redline.

Seem to be starting at about 29 mile to the gallon in the old or someone between 9.6 and 9.9 litres to the 100 km in the new.

 

VS
V6
Series Two
Automatic Transmission
Berlina
Sedan
CAI (Cold Air Intake)
2.5inch Exhaust
35psi
15”
Hardly stop mayb one set of traiffic lights during the week.
10mins
20kgs
Just Myself
Safeway
100-110
149k
Foot down Sometimes
40%

Week One
Regular- 530kms-48.27ltrs used- 9.1avg/100kms
week Two
Regular- 500kms-43.23ltrs used- 8.6avg/100kms
Week Three
Regular- 520kms-47ltrs used- 9avg/100kms

After the Third week i filled up but didnt reset the computer and for another 12/13ltrs i ended up traveling 59ltrs/656kms

 

I didn't fail to read anything kopper. Sorry if I gave you that impression. But in my circumstance my fuel consumption doesn't change much from week to week, because I live in the bush & am on the open road most of the time. :wave:

 

My 10c on K&N air filters are they don't improve performance. Sure in their catologue it shows k&N flow better than a paper element filter, but it does'nt say oiled or dry, slightly used or brand new out of box. The only advantage is you can regularly clean the filter at the cost of filter oil and degreaser.

 

i've run ULP,PULP and BP ultimate. I get the best km's out of PULP, PULP=350KM, ULP=280, Ultimate=200!, I give my car a hard time (once it's warm lol) and noticed the ultimate would last ages when driving like a grandma but then would suck it back when my foot went down. ULP gulps down grandma or boy racer, and PULP is the best all round economy for me. My car CAN get 500km around town if i baby it on PULP and worse on ULP.

PS. I'm interested to see what the K&N does to the fuel.