[AlanHo]

I am a member of the UK KIA Owners club forum and find some of the posts there in the Ceed section highly relevant to our issues with the i30.

A recent post there interested me which compared the economy of the Ceed compared with a Golf and the way the figures were distorted by odometer errors.  I am aware that my previous i30 and my new one both have inaccurate odometers which needs to be taken into account when calculating the fuel efficiency of you car.

I think you might find the post by "Sport Wagon" on the 11th June quite illuminating.

http://www.kiaownersclub.co.uk/forum/let-us-know-your-mpg_topic1022_page41.html

[diablo]

It can be misleading for MPG calculations if the odometer is out by a few percent. I've checked with a speed app on my Android phone that my speedo is right - well it is very close. Assumed that the mile counter was right from that but maybe it isn't?

Just installed a mileage checker app on the phone and will use it next time I do a run of more than 20 miles.

[Alasama]

That's an interesting story.
I have been believing in odometer when talking to friends about the fuel consumption, but now I have to consider that different odometers equipped on different cars could make distinct difference.
However, I believe odometer could over read the actual mileage. Because its calculation is based on the rolling wheels, and the wheels are not perfectly slowly rolling on the road surface  but always the frequent vibration and bounding when driving. If this makes sense, longer journey will generate larger difference. Perhaps that's why Ceed made some compensation to the odometer, but just made too much.