"Hand on heart, I know I haven't put any petrol in my diesel truck," says Lizzy Smith.But the workshop has been just as adamant - fuel contamination did the damage.Smith's 2017 Ford Ranger has been off the road for four months while she disputes that cause with South Auckland Motors.The turning point has been coming to Fair Go with the results of a fuel sample test that the dealer and service agent claimed was confirmation of contamination, but which experts Fair Go spoke with say is anything but.The truck suffered a sudden mechanical failure in January, complete with loss of acceleration,...…"Hand on heart, I know I haven't put any petrol in my diesel truck," says Lizzy Smith.But the workshop has been just as adamant - fuel contamination did the damage.Smith's 2017 Ford Ranger has been off the road for four months while she disputes that cause with South Auckland Motors.The turning point has been coming to Fair Go with the results of a fuel sample test that the dealer and service agent claimed was confirmation of contamination, but which experts Fair Go spoke with say is anything but.The truck suffered a sudden mechanical failure in January, complete with loss of acceleration,...WW…