Adding vehicle with some missing odometer readings
 

Bought a new vehicle, have the odometer reading and it was a full tank

Have 4 other partial fill up details Litres/cost but no odometer reading

and a full tank from today with Odometer reading

Have tried adding them all gives 264mpg, tried deleting the no odomter fuel ups and adding them to the first fill but gives 264mpg

Any suggestion on the best way to proceed ?

Perhaps the trip meter tracking method would suit you better? Doesn't matter if you miss 1 or 101 fuel ups, and you can still add partials if you want, it's my preferred method.

A missed fuelup will clear the issue. Check the last complete fuelup as a missed fuelup and it will reset the count.