hi all just got 2013 fabia monte carlo 1.6 tdi 105bhp   just put fuel in it say's on dash 225 miles  i.ve done 26 mile's  and now says  150 miles .. i've lost 49 miles of fuel some were or is it just a fault with it... thanks for any advice ..... 

The range is being calculated from recent 'average mpg', and that is not very accurate.

You have the same fuel in as before the numbers changed.

 

if you are getting 40 MPG & you have in 9 gallons you will get 360 maybe, maybe more, what the range shows can change if you drive quicker, 

or slower, or mash the throttle for a while,

if you are getting 30 mpg recently it might show 270 and you might travel 360 miles.

o.k. thanks was a bit worried if it was a fault thank's for your help ...

Also be aware if you brim the tank the gauge will stay on full for ages and not move

Drops quite quickly after that tho!

Enjoy the car