Fuelling up with cheaper petrol has left a Wellington couple out of pocket by more than $7000.
And, despite taking a claim to the Motor Vehicle Disputes Tribunal, they won't be getting their money back.
Aron and Adelle Bailey complained they were never told by the car yard that sold them their Volkswagen Sharan that the European car must be fuelled with 95 octane petrol, rather than the cheaper 91 octane.
There was also no sticker on the fuel filling area to indicate which should be used.
In July last year, 23 months and 13,000km after they bought the car, the couple's mechanic told them damage to a piston was likely caused by their use of 91 octane petrol, according to the tribunal findings.