Huge spike in consumption??? Opinions??

[sneaky]

Originally Posted by Yellow_Festiva

Sorta.... Will allow Ford to make me happy before I say more... Let's just say I didn't get what I paid for....

i was thinking there was a rag stuffed/sucked in to the intake.

hopefully they sort it to your satisfaction.

and yep, i would have said air filter. in my supercoon i did a decent trip (central coast to coffs) and the economy was rubbish, hadn't improved from my short stop/start trips. when i got home i changed the air filter and the economy improved heaps.

[mik]

the car has had a bit done to it with the tyres ,brakes, service etc, you might find down the track a bit, it may come good somewhat, i would definitely say my xr6 economy suffered slightly when my young brother borrowed my car on my birthday and and bought the car back with bigger after market wheels on it, so it wouldn't surprise me if wheels might take a bit of the edge of your mileage.

[WILDB]

I would be imagining that the air filter wasn't sitting properly in the box/not sealed or something along those lines from what you've written.

[Crazy Dazz]

Hmm, WHAT software did they update? In an old skool diesel its pretty easy to stuff your economy by squirting more diesel in, or messing up the advance. I imagine all such things are micro-controlled by the computers in yours, but even so it is possible to get “more power” or “more smoothness” both at the expense of economy, which is why I ask about the software. Even if it was just for the tranny, if it has changed shift-points, etc, that could be a factor. Or if it HAS a lock-up torque convertor, maybe that is nolonger functioning correctly.
If your car feels less powerful, I would be looking at the brakes, including the handbrake.

It will be interesting if you can identify the source of the increase.

[burnz]

Originally Posted by Yellow_Festiva

I generally fill up at Shell opposite work, but seeing as I'm on holidays I have been using the local independant that is 12-14c/pl lower than the big names.

Tanks all

Jason
selective post burnz

for them to be that much cheaper would be a higher use of biodiesel.
which contains less energy so more fuel used.

[Yellow_Festiva]

Originally Posted by Crazy Dazz

Hmm, WHAT software did they update? In an old skool diesel its pretty easy to stuff your economy by squirting more diesel in, or messing up the advance. I imagine all such things are micro-controlled by the computers in yours, but even so it is possible to get “more power” or “more smoothness” both at the expense of economy, which is why I ask about the software. Even if it was just for the tranny, if it has changed shift-points, etc, that could be a factor. Or if it HAS a lock-up torque convertor, maybe that is nolonger functioning correctly.
If your car feels less powerful, I would be looking at the brakes, including the handbrake.

It will be interesting if you can identify the source of the increase.

Part of the auto service is the update if there is one available.

Have felt no difference in power, shift points etc.

I jacked up the rear and spun the tyres, both spun with no resistance so there is nothing dragging as I'm driving.

I'm leaving Melb early tomorrow and will stop by my parents place in the Southern Highlands on the way home. I have my old wheels and tyres stored in their shed so will swap em over again, reset consumption and compare before and after readings. They are an hr out of Syd so it should be enough to see any change, if any.

Will post my findings tomorrow.

[Yellow_Festiva]

Originally Posted by burnz

for them to be that much cheaper would be a higher use of biodiesel.
which contains less energy so more fuel used.

Left Syd with full tank of the cheap fuel then filled up 3/4 tank with BP 3hrs out of Melb with no change at all. Will fill up again with a branded fuel prior to leaving to see if the diesel was a factor, but I doubt it.

Thanks,

Jason.

[TheSneakiness]

In my diesel I used to average 8.6lt/100km but now cannot get it below 9.0lt/100km.

I believe tyres may be a factor, however the DPF system in the Mitsus are bloody terrible and clog up the upper and lower manifolds with black soot which would cause rough running.

Keep up the diesel additive for cleaning the engine, and just watch the tyres as well.

[Franco Cozzo]

Originally Posted by Yellow_Festiva

Left Syd with full tank of the cheap fuel then filled up 3/4 tank with BP 3hrs out of Melb with no change at all. Will fill up again with a branded fuel prior to leaving to see if the diesel was a factor, but I doubt it.

Thanks,

Jason.

Was that at Glenrowan BP on the hume?

[Yellow_Festiva]

Originally Posted by Big Damo

Was that at Glenrowan BP on the hume?

Correct Damo.

[Yellow_Festiva]

Ok... the mystery is solved!

New tyres... nope, diesel... nope, pressures... nope, dodgy 60K service... nope.

It's all about average speed, of all things.

Drove back from Melbourne today. Once I got on the Hume I decided to do a little experimenting seeing as the traffic was minimal and I had no real rush.

* Reset consumption and set GPS to 110km/h.... steady consumption of 5.7L per 100km.
* Reset consumption and set GPS to 104km/h.... steady consumption of 5.1L per 100km.
* Reset consumption and set GPS to 98km/h...... steady consumption of 4.7L per 100km.

Each reading after cruising for 30-45 minutes on each setting. Factory figure is 4.8L per 100.

Pulled off the freeway to visit parents who live off the Hume in the Southern Highlands.

Dropped to 90km/h and 10 seconds later average consumption dropped to 4.6L per 100km and held till I pulled into their driveway.

When I had the old tyres, I would drive at 105 indicated on the speedo. In reality I was doing 98-99 as the tyres were well worn and there is also a bais to read under not over.

So there you go. An increase of 12% in the average speed produced an increase in consumption of 21%. Over a long distance that will easily add up. Had I dropped my average speed to what I usually drove at, I would have made it on the 1 tank.

Cheers all,

Jason.

[burnz]

sounds like you need full underbody aero fitted.

[zilo]

Originally Posted by Yellow_Festiva

Ok... the mystery is solved!


So there you go. An increase of 12% in the average speed produced an increase in consumption of 21%. Over a long distance that will easily add up. Had I dropped my average speed to what I usually drove at, I would have made it on the 1 tank.

Cheers all,

Jason.

I seem to recall some years ago that the wind resistance/drag is squared betwen 80-100km/h and then again at 100-120km/h.

Seems to correlate to your findings.