80w 90 Gear Oils: Are they all the same?

[Red Monster]

Both my Yamaha kicker leg and my Volvo stern drive leg take 80w 90 oil. So do I need to use two different types of oil: the expensive Volvo stuff for the Volvo leg and Yamalube for the kicker?
Thanks

 

[SteelyDan]

What volvo outdrive do you have? We have been running penzoil 30wt in the 280 with no issues. A quart of yamalube for the kicker isnt all that expensive and keeps my warranty happy.