Just bought a 2010 1.4 diesel. I've just filled the car up to the top this morning and looked at the trip computer.

I thought I would get more miles out of one tank instead of 293miles to empty? Will this number rise if I drive the car and raise the mpg?

My dads 06plate can get 400miles to a tank??

I changed from a 1.25 petrol to a 1.4 diesel thinking that it will be more economical.

Also, there's a little black box attached to some wires presumably under the front passenger seat. What is it?

Hope someone can help

The predicted mpg adapts to your driving so will go up over time, it may have been driven around town by the previous owner so that is why it appears so low.

Ok. Thank you Kevin for your reply. Its currently around 52mpg at the moment. I'm sure I'll raise the mpg when I go to work on Monday.

Not sure on the black box (photo may help?)

however for the mileage, do yourself a favour and disconnect the battery. Wait for half an hour then reconnect it. The car will be in a learning state to suit your driving, rather than adjusting over many many miles to your way of driving, it should just start to learn straight away.

Sorry for the late reply. Here is the photo of the 'black box'. I'm sorry this might be simple answer. I don't really know much about cars.

By the way I filled it up today and it read that I had 429 miles til empty :)