Premium or Regular Fuel?

[fisherguy123]

I have an 82 merc 50 which seems to run fine other than a bit of hard start when it`s cold . Had my son out in it the other day ....he has a snowmobile and a motocross bike and runs premium fuel in both. He thinks I should use it in my outboard as well. Should I take his advise or would I be wasting money ?

 

[Silvertip]

Re: Premium or Regular Fuel?

If you have a thick wallet go ahead and run it -- but it is does not benefit the engine in any way. In fact the engine cannot take advantage of the higher octane because it cannot advance its timing automatically. Since the engine was designed for regular grade fuel, it is simply wasteful to use it. Engines with knock sensors for example (like your car or truck) can take advantage of it because it has an engine management system that can advance the timing to take advantage of the increased octane. Higher octane by the way is required to reduce detonation common on high compression engines -- which yours is not.