Top speed; how much speed is gained without ethanol?

[JWPrendergast]

Has anyone compared their top speed (or how the boat runs) with a full tank of non ethanol vs regular pump gas with ethanol? Im hearing there might be a few mph increase, but likely not much. Just curious what you guys have seen.

 

[Glassman]

That's an interesting question. Do you have that readily available by you?
I can only find unleaded 100 octane race gas with no ethanol out here (was over $10 a gallon last time I checked) I use it from time to time to mix with 91 in my turbo'd RZR.
And I won't be putting that in the boat anytime soon.

 

[JWPrendergast]

Im moving to a place on the St Johns River that has lots of places to fill up with non ethanol fuel; I definitely plan on trying it. Just wonder if its worth the cost.

 

[BoaterGuy]

The Ocean Pines marina in Ocean City MD has ethanol free gas. I will also try this on Memorial Day weekend.

 

[Julian]

My marina has non-ethanol....didn't notice any difference, but didn't "test" it either. The only difference I noticed was my gas gauge readings being different. There was a discussion about this and how ethanol and pure gas cause our gauges to read differently....

 

[txav8r]

The boat is set up and optimized regular unleaded gas with up to 10% ethanol added. Running anything other than that will not gain any more performance, if anything, you might suffer a little. It won't hurt it to run non ethanol, but many of the marinas only sell the higher octane versions, and that really gets outside the optimum envelope. But again, I haven't heard any negatives, other than a loss of performance. Running non ethanol fuel won't reduce the need to use fuel stabilizer either. And Julian is right, the engine and ECU is set and expects a certain burn ratio, rate, density, and flashpoint. If you use a different gas, those are off and the engine and fuel system will mishandle that gas to a certain degree.

 

[BoaterGuy]

Thats a good point @txav8r, I forgot that the marina only sells mid-grade gas. I'm not sure if that gas has made it into my Yamaha yet, but my 3.0 Merc sure liked it.