Hi all! I've had my 2nd hand Octy 1.9TDI for just over a week now and am enjoying it very much although somebody has already caught my n/s wing mirror and taken a slither of paint off down to the plastic! :(

Anyway, I've got a question about the fuel gauge. Is it linear reading or not? The reason why I ask is because I filled the tank and when it reached the 3/4 mark, I'd done 200 miles or so but then I could only do another 100 miles and it had hit the half way mark!

My driving style hasn't changed between the two stints although if I get 600 miles out of a tank I'd be happy anyway.

Also, according to the OBC average MPG, I'm only getting around 48MPG but most people on this forum seem to be getting in the 50s...is something wrong??? Any opinions much appreciated. Cheers.

The Mk2 diesel is unfamiliar to me, but I've never yet experienced a fuel gague that is perfectly linear, rather it's pretty common that it takes some time from full tank to 3/4.

Fuel consumption: once again I know nothing about diesels, but I guess that consumption increases in cold weather just as with petrol engines? So a winter week may not be the best comparison, especially if it's been cold around your place. Also, with a new car maybe you've tested its resources just a wee bit?

Check your tyre pressure - if you put in 2-3 extra psi above recommendation it won't harm the tyres or affect wear but it could add another 5 % to the mpg figure

If you fill your tank up as far as possible the float in the tank that is connected to the fuel level sensor is forced up to the tank top and actually submersed in fuel. You will have to do many miles of fuel burning to allow the fuel to get low enough for the float - to float.

From then on you will get sensible readings. The trouble is none of us knows when the float actually floats instead of being submersed.

If you fill your tank up as far as possible the float in the tank that is connected to the fuel level sensor is forced up to the tank top and actually submersed in fuel. You will have to do many miles of fuel burning to allow the fuel to get low enough for the float - to float.

From then on you will get sensible readings. The trouble is none of us knows when the float actually floats instead of being submersed.

That's interesting, so all other things being equal, once the needle starts to move off the end of the scale it should be a linear progression? I presume the tank needs to have a more or less constant cross sectional area as the level drops for the needle to read accurately unless this is accounted for?

I would say that it's definitely not linear on the last quarter of the gauge. It seems to drop much faster from 1/4 to empty than it does from half to 1/4.

It was the same on my Mk1 Octy and the Bora I had before that.