Scanguage 2 issue? (MPG reading not matching reality on Jetta TDI)

[joes02tdi]

Well I just purchased a scanguage 2 used and it seems to work perfectly fine, but the mpg function seems to be way off. I own a 2002 Volkswagen jetta tdi and I have been averaging my mpg to be around 38 using the tank divided by mileage method but the scanguage is always showing around 30 even or less on the highway my commute to work is 10 miles each way and it's at around 60 mph and It reads around 27 mpg. Where is all the mileage I am getting to average the tank at around 38 if I am always getting such low mpg. Sorry if this is a stupid question im just a little confused by this.

[euromodder]

Have you put it in the right mode , diesel A or B ?
There's an explanation of how to check that in the manual.

Then, you need to calibrate the Scangauge to the car - and your driving style to some degree - again, instructions on how to are in the manual.

When you correct the amount you filled up against what the SG thinks you used, correct it only half-way towards the right number to avoid overcorrection swinging the other direction.

[ChrstphrR]

Be prepared to be adjusting your "correction" factors when you enter your refill numbers, as well.

I set my trip odometer to the tank when I refill -- compare your "Tank" stats on the SG2 versus your fuel-up volume the next fill -- AND SG2 distance travelled on a tank vs. your trip odo. Bring a calculator, or have one on a phone, because the SG2 doesn't perfectly match how the TDIs meter out their fuel.

In my experience, this is especially the case, if you switch between 100% City vs 100% Highway tanks.

[UFO]

The TDI needs massive correction out of the box. Enter the correct displacement and diesel A, your initial correction will around 15% - 20%.

[99metro]

Apples to Oranges but on my Cummins, I just changed the displacement of the engine to correct for fuel economy. I believe my 5.9L is set for 8.0L in the SGII. Makes it about right. I left the tank gallons, speed adjustments and anything else to the correct values.

One thing to do is to always fill up consistently. It is easy to not fill all the way or overfill tank to tank. The best way is to fill-it-til-you-see-it.

[refilled this morning. SGII was set at 8.0L] FYI

[joes02tdi]

Well I filled up this morning and re calibrated the scanguage and it seems to be working a lot better now. I averaged 40.5 mpg on the tank using the tank division method and that is awesome for an automatic with a good deal of coty driving . and so far the mpg instant reading has been pretty good around 36 mpg. So thank you guys for your input.

[SubSonic]

Hi,

I'm also having a little issue with a recently installed SGII into a Peugeot 206 1.6HDi. Currently moving towards my 3rd tank refill and calibrate, but the cars trip and odo reading are indicating a 80mpg reading while my SGII is reporting 59mpg. ( some hypermilling done to get 80mpg btw ).

The driving is very constant as I only use the car to commute to work ( same route each day ) and refill's have been at the same pump everytime. My gauge however does not show all of the sensors, with many blank. The one I'm am a liitle concerned about is the TPS ( blank ). Many others do show like, RPM, MPH, MPL, LPH, cWT, BST, LOD, cIA, etc.

The gauge is set to metric with only the MPH being imperial. I have tweaked the TPS setting to around 12 which looks about right when comparing driving styles ( coasting in neut, engine braking ).

The comments so far are really making me think 'why did I buy this thing if it has to be corrected so much?' Having to alter engine capacity is not why I brought a so called percision instrument... To only then fudge the calibrated figures later.

Does anyone here run a SGII on a peugeot HDi or similar Turbo D, so that I may contact them to compare findings?

regards

Sub

[kingsway]

I have an Ultraguage with similar issues. It would be nice if it was calibrated out of the box, but by tinkering I have got it to the point where it is reasonably accurate..

The main thing is that I now have some sort of positive feedback when trying to save fuel. If I didn't have the encouragement of the gauge-reading as I drive, I would probably be much less willing to go to the trouble of P&G' ing!

[zx1100r]

Originally Posted by joes02tdi

Well I just purchased a scanguage 2 used and it seems to work perfectly fine, but the mpg function seems to be way off. I own a 2002 Volkswagen jetta tdi and I have been averaging my mpg to be around 38 using the tank divided by mileage method but the scanguage is always showing around 30 even or less on the highway my commute to work is 10 miles each way and it's at around 60 mph and It reads around 27 mpg. Where is all the mileage I am getting to average the tank at around 38 if I am always getting such low mpg. Sorry if this is a stupid question im just a little confused by this.

The Scangauge II doesn't work well with the tdi, even if you get the mileage close on the highway then city is way off or the other way around. I returned my scangauge for the that reason and tech support was useless.

[NachtRitter]

I've liked having the SGII in my TDI actually... works really well.