Thread: TD6 ODOMETER

G'day Jimbo,

In short, Yes.

It is possible for the the pulse count for a given distance to be set differently between the speedometer and the odometer.

These and lots more values are set in the IPAC ECU.

Cheers,
Iain

Can these values be read? Reason for asking is that with a 100l tank the odometer only goes up by about 500km which is 20l/100k. The average fuel readout shows approc 11.2l/100km which in actual fact works out to be 900km range.

Hey again,

Yes, the values can be read although you'd need something like a Faultmate, Autologic, VCS or similar.

Checking your odometer accuracy is pretty easy these days with GPS technology so pervasive. Find a nice long straight(ish) road and mark start and finish points for a km or two as indicated by GPS. Check what your odo says against the GPS. Even those highway sign checks are fairly good.

The 100l tank is a bit of a trap as you can't use all of it anyway. I think you only get about 97 out of it before you run the lines dry (never a good thing to do as it is a ***** to re-prime).

Depending upon how often you reset the average, this may not be unreasonable. Mine to shows 11.6l/100km currently but if I do all my driving on this tank around town I'd be lucky to get much above 600km from the tank. The point is it's an average and I don't think the math for these numbers is done entirely on actual consumption. Parts of it have to do with flow rates, sure, but some of it has to do with pedal position, rpm, gear and so on.

The range indication, I think, uses a sort of "instantaneous" value to make the calculation. You can see this in action if you watch your range value while you drive up and down hills on the highway. It will go down as you drive up hill (and burn a little more fuel) and go up again as you descend (and you burn much less fuel due to less load). I read a good writeup about it some time ago but can't track it down just now. So, going on memory here. A tenuous thing these days!

I use the numbers as a guide but do the math myself by working out how far I've traveled (my odometer is reasonably accurate 997 actual vs 1000 indicated) and how much to top off the tank.

I've found almost instantaneous reading on fuel consumption of anything from 4l/100k to 45l/100k. So an average of 11.2 indicated may not be unreasonable but you still may only get 20-15l/100k around town.

If your own math suggests actual range of only 500km on the highway then you may have a mechanical issue somewhere. Around town 500km range from a tank may not be unreasonable depending on terrain, traffic and driving style.

Cheers,
Iain

I think I might have solved my own delimna. The fuel tank dropped to exactly half today so I filled to the first click off. I though it should have taken 50l but cut off at 38l. So working out the maths I am getting 12l/100k approx. I never gave my fuel gauge accuracy a thought. Jim

The fuel gauge on mine is inaccurate as well. 1st half of the tank goes very quickly, but it will go for ages on the bottom 'half'. I can get mine down to the needle sitting right on empty, yet only being able to squeeze 85 litres into it. I don't mind - it gives me a bit of piece of mind that if I get stuck with a low tank, I should have a bit to play with to get it to a servo.

My biggest problem is the inline pump which is on the way out I think, as sometimes if it goes below about an 1/8th on the gauge, it can be hit or miss if it starts again... perserverance usually pays off and once it is full, it never has any issues.

Cheers - Gav