R23 OB F200 ECU Flash Upgrade Results

[Rocky Lou]

Very interesting and, hopefully, we get some other comments since fully understanding Octane and our engines is way above my pay grade. The topic reminds me of when my fishing club members discus the efficacy of using wire or braid on downriggers. When I first bought my boat in 2019, a highly respected Yamaha master mechanic told me, 'you can use 87, but, your 300s become 250s'. I generally don't believe that is the case, but, I still hear Yamaha folks making the claim.

 

[Submariner]

Very interesting and, hopefully, we get some other comments since fully understanding Octane and our engines is way above my pay grade. The topic reminds me of when my fishing club members discus the efficacy of using wire or braid on downriggers. When I first bought my boat in 2019, a highly respected Yamaha master mechanic told me, 'you can use 87, but, your 300s become 250s'. I generally don't believe that is the case, but, I still hear Yamaha folks making the claim.

I've heard similar, and I agree with you. I don't think 87 octane would make the F300 an F250. But I do think 87 octane fuel would result in less than 300hp on the stock tune.

 

[Mike and Sarah]

I will say when I have filled with 89 octane in Oak Harbor I see / feel no difference in power or fuel economy.
The reset of the time I am running 87 octane non ethanol.