Are you sure? AFAIK your MQ500 use G 052 527 which is either 75W or 70W-75 GL-4
MTF (refer to its SDS). 27.6 mm²/s at 40 °C, 6.1 mm²/s at 100 °C, as light as it gets. And
same MTF as MQ350 transmission (GTI, GLI, S3, R etc.).
Not surprising. Double the weight will inevitably cause shifting...