According to my handbook my manual 6 speed has Castrol BOT130 at new (4 years ago). Since this oil is unobtainable I have just drained and filled with Ford oil (WSD-M2C200-C) as the gearbox is a Ford. All logical but the outcoming oil looked red ; could Volvo have used anything handy or is BOT130 red? Do all manual transmission oils mix happily? Synthetic and non synthetic? I didn't have enough oi to flush; should I be worried? Opinions welcomed.