four stroke oil for mercury 115 hp

[pointblank1000]

Can I use a automotive four stroke oil for my 2005 115 hp mercury four stroke? Say castrol 10w30?
What about gear lube? Do I have to use mercury specific gear lube or can I use a certain weight auto
rear end lube?

 

[Mfulfer]

Re: four stroke oil for mercury 115 hp

No! Use the correct Merc oil. auto engines run at around at 220 deg. while the average outboard runs at 130 (give or take based on the engine) Merc oil was designed to support that engine. (or yamalube...that is a yamaha powerhead) Also get the correct gear lube...yes more cost... but never risk something expensive for something cheap....it is a bad plan. (also make sure your running the correct NGK spark plugs)

 

[Chris1956]

Re: four stroke oil for mercury 115 hp

Your Merc motor oil is likely rated FC-W for Four Cycle, Water cooled. That kind of specialty oil is avail widely, even at Wallyworld. Gear oil is "Marine Gear Oil for mechanical shift outboards". Also avail at Wallyworld. Any brand is acceptable.