Scangauge accuracy for fuel efficiency

[patroltrav]

Gday guys,

Just wondering how accurate these scangauges are meant to be ? I have a 08 GU 3.0TD manual and I was just wondering what you other guys are getting when travelling at certain speeds?
Only me in the car unloaded, not towing, on cruise mine is saying
80 klph = approx 8 klh on the gauge
90 klph = approx 16 klh on the gauge
100 klph = approx 20 klh on the gauge

I didnt think the efficiency would be that bad at 100 kmh ?? It seems running around town is giving me better figures than on the highway

[Maxhead]

Hey Trav, The scanguage takes a few fill-ups before the are accurate(mine was anyway)
Not familiar with klh meaning as I only use liters/100 (lph) but it is not unusual for CRD motors to burn more on the highway and some are very thirsty and others not so much.

[the evil twin]

Mine is pretty much spot on for "AVG"

You have to watch "LPH" as that is instantaneous as reported at the sample times from the ECU so can be a bit hit and miss but gives a good idea of trends.

My fuel useage sky rockets at about 105 KPH and I get significantly better figures around town and up to 100KPH than at hi speed cruise BUT I have a lot of Mods so no comparo to factory... I've seen it as high as 17.5 but never 20's

The one small weakness of the Scanguages is with Chipped engines if the Chip changes the fuel rail pressures after the ECU and is open loop BUT the Scangauge will still be pretty damn close.

[patroltrav]

Sorry about that I did mean the lph as that is one that i have up aswell as the avg, boost and coolant temp.
Yeah I have only done the first fill on the tank so hopefully it will get a bit closer.
The avg seems to always be about 17 or 18 after my around town but from my rough fuel usage calculations i got about
14/15 lph.

[the evil twin]

OK, thats normal for your first tank (the error I mean).

The Scan gauage initially just uses a standard 3.0 Litre figure for injector flo rates and it works out fuel used by "standard fuel flow x how long the injectors are open". When you adjust the amount of fuel you add to the tank at your first fill that + or - which shows as a percentage in your adjustement is how much the Scanguage will recalculate with so it will now be "standard fuel flow/percentage correction x injector cycle".

IE if the vehicle takes 5% less fuel than predicted the Scanguage will now deduct 5% from the calculations of fuel flow and fuel used etc and from now on the AVG and LPH figures should be much more accurate. Another fill or two and you will not need to touch it again.

Resist the urge to change that % figure every fill... if the fill is within about 2 or 3 litres per 100 of what is expected those small differences will only have you chasing your tail. Only adjust it if the figures are out consistently one way IE always takes more fuel or always takes less.

You may get the odd "weird" figure if you do a tank full of work out of the norm. Say, a hell of a lot of lo range slugging you normally wouldn;t do whilst on Hols at the beach for example. Again, don't adjust the fill up figure. All you are doing is putting in an error for the next tank useage which will be back to normal.

I normally take on 120 to 150 litres at a time and the Scangauge is normally with 1 or 2 litres either way BUT has on two occasions been out by 6 and 11 after some really hard yakka and a 1,000 K hi speed run out back of WA.

[Bigrig]

Excuse my ignorance one and all, but what is the Scanguage? Is this another variation of the ECU device I've just bought, or is it something completely different? If different, what are the benefits of having one? (and what do they cost?).

Thanks in advance!

[the evil twin]

Excuse my ignorance one and all, but what is the Scanguage? Is this another variation of the ECU device I've just bought, or is it something completely different? If different, what are the benefits of having one? (and what do they cost?).

Thanks in advance!

Scangauge is the OBDii compliant display so works on CRDs and nothing else Patrols wise... ECU Talk works on the other models
http://www.scangauge.com.au/

Being OBDii I can use it on all the family vehicles... Mitsi, Hyundai, Ford and my beloved Pootrol

[Bigrig]

Scangauge is the OBDii compliant display so works on CRDs and nothing else Patrols wise... ECU Talk works on the other models
http://www.scangauge.com.au/

Being OBDii I can use it on all the family vehicles... Mitsi, Hyundai, Ford and my beloved Pootrol

Ahhhh .... Thanks mate!!

[patroltrav]

Cheers Evil twin and NissPat I just did my next 1/4 tank fill up and its already providing more acurate results.
Looks about 2-3 lph better accross the board so it is making alot more sense now.

[Maxhead]

Cheers Evil twin and NissPat I just did my next 1/4 tank fill up and its already providing more acurate results.
Looks about 2-3 lph better accross the board so it is making alot more sense now.

Good to hear mate. Those figures looked way too high