Dash readout V's actual

[Draigflag]

Originally Posted by BDC

Scangauge only has tools at its disposal which are already present on the vehicle. There are no fuel flow meters on cars, and all MPG meters only use the pulse width from the car's ECU to the fuel injectors as a measure of fuel flow. So the scangauge and all other MPG meters (in production vehicles) are limited by the accuracy of this signal.

Some people here are reporting better/more accurate readings from the Scangauge than the cars computer, otherwise, what's the point buying one just to get the same info the cars computer gives you?

[trollbait]

Scangauge uses the same inputs as the car's computer to measure the fuel used, but the set procedure involves calibrating with a couple of fill ups from the station.

[BDC]

Originally Posted by Draigflag

Some people here are reporting better/more accurate readings from the Scangauge than the cars computer, otherwise, what's the point buying one just to get the same info the cars computer gives you?

Not all cars allow you to see that data. And the scangauge does indeed have "calibration parameters" which are nothing more than scaling coefficients, but some folks use them to make their scangauge line up with their empirical data.

[Draigflag]

I see. Here's the thing I couldn't work out, car gives current MPG, trip MPG, average speed, distance, range but the one that interests me is "fuel used". Surely if I brim the tank every time, once the "range" reading goes blank (usually about 80-90 miles) I could use the fuel used (measured in UK gallons to one decimal place eg 10.3 etc) reading to work out roughly how much is left. I might start making notes of the "fuel used" reading and compare it to the fuelly calculations. If it proves accurate, I can then use it as a guide once the range is empty.

[Moseng]

Originally Posted by SteveMak

luckypants: Can you tell me where I can get VAGCOM cable and required software? I'd like to get into these VAGCOM mods.

Try Amazon for this. You will surely get the discounted offers there.

[litesong]

Originally Posted by BDC

There are no fuel flow meters on cars, and all MPG meters only use the pulse width from the car's ECU to the fuel injectors as a measure of fuel flow.

Could your information be a reason that burning E0 seems give a slightly more accurate reading of mpg than the use of E10 gives, since E0 averages 8%, 8%, 7% & 5% better mpg over decades, than E10 in my 4 cars?

[BDC]

Originally Posted by litesong

Could your information be a reason that burning E0 seems give a slightly more accurate reading of mpg than the use of E10 gives, since E0 averages 8%, 8%, 7% & 5% better mpg over decades, than E10 in my 4 cars?

No, ethanol content wouldn't have anything to do with the accuracy of the fuel flow calculation.

[Plandergan]

I've also got an issue with indicated versus real mpg. In September I traded my Audi A1 1.4 (petrol) which I'd owned for 22 months from new, and covered 40,000 miles in that time. During that time I very carefully monitored real consumption and compared with that indicated by the in-car computer. It NEVER differed by more than 2 mpg, and was usually bang on.


My new car is another Audi A1 (1.6 TDI) the fuel consumption is (unsurprisingly being a DERV,) far better, the main reason that I bought it, however the difference between the indicated mpg and the real figure is huge – anything up to 12 mpg.Has anyone else seen similar?Is this another attempt by VW Audi to mislead the public?

[Draigflag]

Hi there. Do you brim the tank consistently? Only reason I ask is that when I fill my car, it clicks off, then it clicks off again, but the truth is, if I gently squeeze the trigger, I get a lot of extra fuel in. Only when I can see fuel sitting in the cap am I happy that I refilled to the same level as the previous tank. Generally dash V's actual readout and 2-3 Mpg different, so 12 seems a bit crazy!

[Plandergan]

Hi
no I always fill until the pump cuts off. I only ever use two or three filling stations, and try and go for the same pump each time to be as consistent as possible. The issue isn't that there's an error between my method and the cars computer, its that two very similar cars (OK different engines, but similar computational software) produce completely different results. I've queried it with my Audi dealer and they say its "odd" - very helpful


P