MPG - How accurate is computer??

[ifti]

I have a MFSW - so I would press the down button on that for a few seconds?

[DJGTi]

I give the button under the stalk a quick press to put it into 'memory 2' position, and hold the button to reset. I do this when I fill up and this gives me an average speed and mpg for each tank. Not got MFSW, but think that one of the buttons does do the same as the reset on the stalk.

The instant mpg is pretty useless. Its easy to get 99.9mpg by just backing off or coasting downhill.

[pitch3110]

I would think the button under the stalk should od the biz...

My A4 DIS is a mile out....The car averages 43-48mpg whne checked between fill ups but DIS shows as much as 50+.
The tech's at Audi tell me this is with tollerence. T#**ers.

I haven't check'd the ED30 yet, but off up to York next weekend to see big son at Uni & can't decide to take my 2.0TDI S-Line A4 or the wifes ED30
Perhaps a few hundred  :evil:in the ED30 would be good to check MPG

ta

[ifti]

Im pretty sure my ED30 resets the average mpg after the car has been switched off for a certain amount of time - not sure what time length it is - but it seems to reset with every trip I make......pretty much how I would like it TBH.

[DJGTi]

Im pretty sure my ED30 resets the average mpg after the car has been switched off for a certain amount of time - not sure what time length it is - but it seems to reset with every trip I make......pretty much how I would like it TBH.

You have 2 memories. No 1 resets after 2 hours of non driving, No 2 only resets when you do it. To switch between the two, flick onto average mpg or average speed and press the little button under the wiper stalk. Hold this button down to reset either memory. (Its all in the manual!)

[Teutonic_Tamer]

I've found 'miles remaining' or 'range' to be dependent on your last average mpg reading, so if your average mpg was 20, your 'range' on a full tank will be lower than if your mpg was 40.

Not quite correct.  The 'miles remaining' constantly recalculates, but displays (in multiples of 5 miles) based ONLY on your last driving habits.  So if you cane the car, the miles remaining will drop considerably - but then if you start to drive it really carefully, you can actually see the miles remaining increase, even without adding any fuel to the tank.

I've found the range to vary from as low as 300 miles to as high as 375 miles (and then stay at that reading for 25 miles because I've been cautious).

You hit the nail on the head.  When you get really low on fuel, you generally start to drive like a granny whilst trying to find or reach your local V-Power/Tesco 99 stockist, thus being economical.  Then when you fill the tank, becuause you were last driving economically, the miles remaining can initially be artificially high - but when normal driving <wink> resumes, the miles remaining drops down quite rapidly.

BTW, Stealth, did you manage to get a Haynes manual?

[Teutonic_Tamer]

I had the one that reads while you drive show 99mpg 

Yup, and some makes of car can read 999 mpg.

The average is accurate,

I personally havn't checked mine, but they are supposed to be within 10% accurate.  However, if anyone does want it to be more accurate, then there is a setting the stealer (or vag-com) can tweak to adjust the accuracy of the MFD mpg readout.

dont believe the 'while you drive' one 

Sorry, but disagree.  The 'while you drive' reading is an instantaneous readout, rather than an average.  And it is very good in helping to drive in an economical manner, just like the old-skool vaccum gauges.

Furthermore, it also helps to show the efficiency gains from the FSI fuel system - comparing my B6 S4 (4.2 litre V8) against my current B7 RS4 (essentially the same 4.2 V8 as the S4, but with FSI) - the v-max fuel readings are noticeably improved on the FSI.  See my sig. 

[Teutonic_Tamer]

How do you reset the average mpg reading?

Don't forget - on the highline, there are two separate 'trip computers'.  Trip 1 simply clears all stored data after two hours from removal of ignition key - so is best used as a 'journey-specific' trip comp.  Trip 2 never clears, UNLESS you either clear it manually, or disconect the battery.

So for calculating tank-to-tank fuel consumption, then Trip 2 is the only one to use (brim the tank, reset your trip odometer, and ALSO reset Trip 2 - then when you next brim your tank, note the readings from the odo and Trip 2, reset then again, and use the old-skool abacus calculations from the actual quantity of fuel pumped into the tank).

[flyingzard]

I am pleasantly surprised with my mpg - 33 mpg over 3000 miles (from new) 

[ifti]

How do you reset the average mpg reading?

Don't forget - on the highline, there are two separate 'trip computers'.  Trip 1 simply clears all stored data after two hours from removal of ignition key - so is best used as a 'journey-specific' trip comp.  Trip 2 never clears, UNLESS you either clear it manually, or disconect the battery.

So for calculating tank-to-tank fuel consumption, then Trip 2 is the only one to use (brim the tank, reset your trip odometer, and ALSO reset Trip 2 - then when you next brim your tank, note the readings from the odo and Trip 2, reset then again, and use the old-skool abacus calculations from the actual quantity of fuel pumped into the tank).

Cheers T_T.
Yeh I reset Trip 2 every time I fill up - I guess its habit since I used to do it with my old car as well.