At the price they charge for Castrol SAF-XO there can be no doubt they "recommend" its use. But to think that it has some special quality that makes it the only aceptable gear oil is to waste money. I wonder how many warranty claims BMW has tried to deny by claiming that Castrol SAF-XO was not used; none I would surmise. I know at least two dealers that do not use it as their standard shop gear oil for services.