Currently conducting a little experiment that may be of interest,
Am now on my second tank of Shell Premium and driving wholly on
Economy.
Previously I used the same petrol from the same shop for a period of a 5 days or so and I got 558kms on power before needing to fill up again.

So now Im on my second tank running on economy and will post results when Im empty. (55 Litre tank)
Of interest though was the number of ks I got out of the first quarter,
on power I got 254Ks before the meter dipped below the 3/4 line,
on economy I got 256ks before the mter dipped, will be interesting to see how much more ks diffence there will be in the long run.
Driving conditions havent changed, them being a mix of both city and country/coastal driving crusing between 70-90ks (yes its dam hard staying at the speed in the name of science!!)

That would be illegal Seriously servos have to have thier pumps checked & calibrated regularly to stop that from happening

Yeah all part of the license i believe.

My brother owns an AU ute and he told me yesterday that he also gets more Ks when in power mode than in economy. Weird s**t but its all true.

Maybe Ford need to rename that "economy button"

How often are they checked tho; seems quites possible to do it n then put it back for a while.
Do they get set dates when it will be tested, thatd be easier for them to work around, or if they knew someone who could tip them off that testing will be soon.
I agree with kit, i put in 35 bucks one day, didnt bother to fill, and i still wasnt even at half way on the gauge, and it didnt go up either with time/driving.
Fkn BP in queensland!

Oh sure, servo's would never do anything illegal like... adding toluene to their fuel supply to save themselves some money. Yeah right.

When I was driving my XF around and I had to stop to fill the LPG I was always filling up the tank from dead empty with more litres showing on the fuel bowser than my LPG tank was actually capable of taking. Every single service station would give me different figure when I filled up, 2 litres over at one servo, 3 litres over the maximum at another, 4 litres over at yet another...
All servo's are just so honest...

Fellas, looks like Derryn is on your side.... and your suspicions are not unfounded.....

http://www.hinch.net/says_archive04/Apr04/19-4-04.htm

Lol @ shell.. 10 offenses with total $5,000 fines....

You are right about the toluene, there was some dodgey operators out there, I think that since then they also have to have there fuel checked. otherwise they could sell ULP as PULP the average motorist wouldn't know the differance.

LPG is a differant story. On a hot day you will get less in you tank because the gas expands more, on a cool day you will get more. I had the same experiance with a duel fuel EA I once had

SHAME! SHAME SHAME!

I get about 400km out of 60 litres in my EF with econ and less than that with power.

Most of the driving is done in hilly terrain. All I do when I go to work is up a hill, down a hill, up a hill, down a hill. And they're pretty big one's too. There's no flat spots on the way to work.

Does anyone in here even know what the difference b/n econ and pwr is? Has anyone payed attention to it?

I have. It doesn't limit the revs at all. That's Holden's trick. Basically all econ 'systems' do a number of things to save fuel, but there's generally one thing they change that makes the big difference, and all the other little things just fine tune it.

In holden's case, you can't redline the engine in econ mode. That's the major change.

In Fords, they delay the kickdown and require less vacuum (i.e more throttle) to kick down. It also in some conditions lowers the revs like cruising on the freeway. In econ your engine does about 200rpm less that in power.

Anyway, one tank is nowhere near enough to get a true indication of what is better. There are just sooo many variables you need at least 5 tanks in each mode to really tell which gives you better economy.

All these things can affect economy no matter what mode you're in.

1 Ambient temp (the colder it is, the longer the engine is in cold start, also you need less throttle and this increases the "pumping effect" of your enging requiring MORE fuel... not less)
2 Humidity
3 Terrain
4 Amount of traffic
5 Different number of cold starts and stopping/starting in traffic
6 Different petrol (even if you get it from the same servo, it is probably a different batch and COULD be different)
7 Cleanliness of fuel system (did you go from regular ULP to premium on the first tank? if you did, this would have cleaned the fuel system, as all PULPs contain detergents, and the economy gains would have been realised on the second tank)

It could also be that in econ mode, the EGO sensor runs a little cooler and may give a lean reading.

Also, in econ mode, because the kickdown is delayed, there is a tendancy to open the throttle faster. This results is far more fuel being injected for the the accel enrichment and will alter your tests. Further to this, if the EF ECU ignores the EGO above a certain amount of throttle (I don't know if it does or not) then you need more throttle to kickdown and this may put the engine into conditions where it's running richer for power.

The other thing you need to do to save fuel is put air in your tyres.

If you run 36psi instead of 32psi in your tyres, you will save between 3% and 5% on your fuel. If you run 40psi, you save even more.

I run 44psi in my tyres. Contrary to popular beleif, there are no adverse effects with running higher pressures in your tyres. The only reason for running 32psi is for ride plushness. Higher pressures have the following benefits:

Better wet weather performance
Better cornering
Better fuel economy
Shorter stopping distances

The higher your tyre pressure especially in your case at 44psi is it will wear in the centre of the tyre more than on the edges.

I run 40psi because it is better fuel economy and it wears evenly accross the tread. Any higher it will wear more in the middle. Any less and it wears more on the outside.

My experiment was specifically on two tanks both with Ultimate 98 (thats all I ever use).
I constantly have better fuel economy in power mode but this was a time when I actually recorded the Ks I got per tank. At the moment I am at 500ks and the needle is sitting on the 1/4 line. I still got 150-200ks to go on this tank.

I reckon in economy mode you apply a little more pressure on the accel pedal because its not giving you as much power because it changes gears a little too early for my liking. When I'm in power (all the the time now) I dont push as hard because it stays in gear longer and changes better. My gearbox is a bit worn which is why it changes better in power than in economy.

Again it will be different among every car.

Overinflation causes the centre of the tyre to wear. That is correct.

Overinflation is when you put more pressure than the max recommended psi of the tyre. This pressure is basically the max pressure the tyre can handle before it starts to be deformed.

My tyres are rated up to 44 psi therefore I run them at that. Also, if you've got low profile (I haven't) the minimum pressure you should be running in them is about 40psi. Put 32psi in a low profile tyre and you lose a lot of performance and cut the life of the tyre almost in half.

Some cheap tyres are only good up to 36psi so even running 40 psi in them will overinflate them.

Another benefit with higher pressure is a cooler operating temperature which increases the life of the tyre.

Edit: Also, how many kms has your EGO sensor done? They get very sluggish when they get old. If you say that the engine conditions stay a bit more constant when you're in power, then a sluggish EGO will have less of an effect that if the engine conditions are changing more frequently (i.e more shifts, more pushing of the accel to kick down etc etc)

I dont know what an EGO sensor is but I guess its done the same as the car 250,000ks.

EGO sensor = Exhaust Gas Oxygen sensor, aka HEGO = Hot Exhaust Oxygen sensor, or just plain ol' Oxygen Sensor.

The EGO sensor is the Exhaust Gas Oxygen sensor and is responisble for adjusting the Air/Fuel ratio so that the engine runs @ 14.7:1 AFR.

No-one ever thinks to replace these but they have a useful life of about 250,000km. After that, they still work and still give accurate readings, but their response time goes up quite a bit.

You can pick them up for about $100 from your local Bursons, although if you've got a new exhaust system, you might already have a new one.

That's another thing.... if you've got extractors, they've probably been designed to work in the 2500-5000 RPM range... so driving around in pwr mode might be in a better rev range for the extractors to work properly.