Well after a fill up mine is still showing 609 miles to go! When infact it's around 400 miles till (I assume) it would be completely empty. I get around 360 miles untill I have 60 miles left by the computer and the light comes on. This is assuming the computer is 30% inaccuriate.

I will try the method to adjust again.

Adam.

 

I've just run another tank through it. I've had a couple of trips into London this week for a training course so it's hit the mpg. The computer said 39.6 average with distance remaining running out at about 465 miles. I filled up at 473 miles with an actual of 39.3 with around 5 litres left. I'm fairly happy with this and after a few weeks of having a fuel computer have decided it's a bit of a gimmicky boys thing and the guage with the light is really enough. However, it's there so I'll have to fiddle with it

 

I've just had a fiddle with mine!

There seems to be two settings which say "DIS"; number 50 and number 51. On mine, 50 was showing 0 and 51 shows 34.2 (I think, I didn't write it down but it's that sort of figure). I changed setting 50 from 0 to -10, hoping that reduces it's figures produced. I wonder what the other DIS is referring to?

I'll fill her up soon and report back in a few hundred miles or so. Incidentally I went through the process again and noticed setting 50 had reverted back to 0, which I assume means I could keep on adding or subtracting percentages for ever, it's not limited to just +/- 15% of wherever it starts. Or it might mean that I didn't change anything! Anyone know if there is a STORE button or anything else I should have pressed?

Dave.

 

Mine did that too, but the remaining figure definately changed, so I'm assuming the new figure becomes 0 as default. The other setting which needs adjusting is the distance remaining when the tank's full as 660 miles is a touch wide of the mark.

 

Quick Update. After 3 runs from Cheadle to Southport this week, 396 miles, tank full to tank full again, I've acheived 40.5 mpg, and the stupid computer claims 9l/100miles which is 50.5mpg, so it is now 25% inaccurate, not the 18% it was before!!

I have obviously tweaked the calibration the wrong way. Doh !

So if it is reading a too generous figure, it would seem that I need to make a +ve adjustment to the DIS setting.

Dave

 

At least it gives you something to do on these long, dark, damp July days!

 

My new Mazda 5 shows a lower MPG figure than I have acheived, trip comp shows 41.0mpg I did 537 from 50.21 litres not bad for the first full tank
That was full tank to full tank 48.98mpg.

Oh lucky me, I do a lot of motorway work normally but that tank was 50/50 about town and motorway without being over cautious as you have to find out how much fun the car is !

 

I adjusted as per the post but all that changed was the distance to go and not the litres/100. Also when I took it in for its service and recall on the pipe it seemed toget reset again.

 

Hi All,

Regarding the fuel computer/guage issues, don't know if this may help. About 5 years back, we had a Picasso which had similar problems. Sounds like those on the 5 work in a similar way. Here's some info I was given at the time.

1) The computer works purely in L/100km. It then does the math to convert to MPG. Rounding up/down can induce errors.

2) The sampling rates for the fuel sensor can also cause problems. On the Picasso, the fuel sensors were 'damped' and only polled every 6 and 80 minutes. The damping being used to cancel errors caused when driving on windy/bumpy roads.

3) When filling, any thing under 6L would not be registered until the sensors are next polled. So stick 5litres in and drive on a straight road for 80 minutes before computer/guage finds the extra fuel.

4) The fuel guage may not be programmed linearly(?) The guage on the Picasso was a strip of 9 leds. I assumed each led = x litres. Not so, each was setto a different amount. If same on the 5, each section of the fuel guage will give differing miles per section.

Hope that helps

Pat