have a dig on Lougle Google as i dont know all the english words to explain it but:
Automotive oils are for Dry Clutch, hence they have all sorts of less friction particels etc on the oil. Those additives are harmfull for a wet clutch, especially on a high revving engines.
rev high, slipp the clutch alot and the additives that are slick make the clutch slip->get hot->cause overheating-> warp the metal plates-> and burn/glaze the friction plates.
the additives will d*ck into the friction plate as any oil does.
wet clutch designed oils have always additives on them that ADD friction, vice versa to automotive oils.
comprende ?
best gear oil ive used so far has been Motul5100 4T motorcycle 15W-50. because its the cagiva's original 15W-50 value and it defenitely made my mopeds rough gearbox very smooth. next im putting it to Cagiva's when my Agip is done.