Since the remap I have noticed a regular inaccuracy in the trip computer on my Octavia. Despite running consistently through about 20 tanks of fuel since I reset the trip at jabba, it still claims I can get 400 miles from the tank once I've filled up.

Each tank full is used at a reasonably conservative pace and I get almost exactly 330 miles from each.

So, what I'm wondering is this.... does the trip computer acually know how much fuel is being used by the car? or is it working on pre-defined tables based on the ammount of throttle being applied?

Assuming this is the case it would explain the difference as I'm actually using more fuel than it thinks I am. However, this also has implications for the "miles to fill-up" figure when it gets very low.

Another possibility is that it has been programmed to make you feel better about you car's economy when you fill up.

I was tempted to email Skoda to ask them but thought they'd just ignore it the moment they found out it was remapped.

I'm sure it can only 'guess' when you have just put petrol in.

Once you are on the move and it can start calculating based on how the car is driven it must become more accurate.

Actually I have no idea and this is just an assumption I made.

That would be the case if you reset "trip 1" or even "trip 2" afetr filling up but surely it can use the figures from each of these to do its calculations?

Or pehraps I'm just expecting too much of it?

It takes the average MPG you have at the time and uses that to calculate how many miles you can get with the amount of fuel you put in. It is not 100% accurate, but close enough.

Presumably it measure the amount of fuel left in the tank and the current average fuel consumption to arrive at the range - this will be affected when you 'brim' the tank because for the first x number of miles the fuel being used is that in the pipe. This causes the computer to think that you have used less than in reality and innacurate readings at the start of a tankful.

Mine almost always 'reckons' on about 420 - 450 at the beginning and ends up at 330 to 350 by the end.

Does anyone know whether this computer is reset at service intervals?