An Auckland woman who caused serious damage to her car's engine by frequently using the wrong grade petrol has lost her compensation bid at the Motor Vehicle Disputes Tribunal.

Suzanna Chan, who bought a 2010 Volkswagen Golf from Top Motors Plus in March 2018, claimed the vehicle was not of acceptable quality after the engine suffered significant premature damage in April 2019, requiring expensive repair.

Chan told the Tribunal that the engine damage may have been caused by an inherent or pre-existing defect, inadequate past servicing and because Top Motors Plus did not service the vehicle before it was sold to her.

Top Motors Plus denied liability, claiming the damage was caused by Chan using the wrong fuel.


Chan had the vehicle assessed by Qualitat European Motors Ltd and Euroline, which found there to be cylinder and piston ring damage.

But Euroline considered the damage to be a "typical problem" with the type of engine in the vehicle, caused by a lack of regular servicing or prolonged use of incorrect fuel.

Chan and her partner Theo De Villiers gave evidence that they used 91 octane fuel in the vehicle approximately 85 per cent of the time.

However, Mr Haynes, the Tribunal's assessor, advised that such vehicles as the 2010 Volkswagen Golf TSI – which has a 1.4 litre petrol engine – must use 95 octane or higher fuel because the vehicle has a turbo and a compression ratio that requires the use of high octane fuel.

Haynes said that using fuel with a lower octane can cause pre-detonation in the engine's combustion chamber that then damages the engine's pistons and rings.

"I am satisfied that the damage to the vehicle's engine was most likely caused by Chan using 91 octane fuel in the vehicle, rather than any inherent fault with the vehicle," the Tribunal said in its decision.

Chan and De Villiers argued that Top Motors Plus had failed to explicitly tell them that they needed to use higher octane fuel.

But then Tribunal disagreed, saying Top Motors Plus had no obligation to do so.


"I consider that it is the consumer's responsibility to make the necessary enquiries to determine what type of fuel should be used in a vehicle, in much the same way as they should make enquiries as to the type of oil, brake fluid or transmission fluid that should be used if they are putting those substances into a vehicle."