What octane fuel is everyone running?

[Amc0825]

Is everyone running 89 octane or higher? Marinas in my area do not have anything higher than 87.

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[RC_Hinojosa]

Is everyone running 89 octane or higher? Marinas in my area do not have anything higher than 87.

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89 octane is the required fuel for the Raptor 400 & 440, 93 octane for the 575

[Amc0825]

Ya I seen that in the manual. My dealership said 87 was acceptable as long as it was ethanol free. I'm not sure what to think about that.

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[MLA]

My dealership said 87 was acceptable as long as it was ethanol free.

Sadly, misleading. Octane and ethanol have no correlation and should be two different conversation. You need to run the recommended oct or the first higher grade available. E-free is great, but you still need to follow rule #1.

[Broke Pilot]

Yep, ethanol is like octane. That’s why all the drag racers are moving to E85 tunes.
Technically 87 with E would be more acceptable than 89.

[zabooda]

Ran my boat for 18 years on 87 octane E10 and no problems. At 5gph, nothing but the cheapest gas.

[Prospersigman]

I run into the same problem in my area...my home base lake is 87 octane only. We go to Broken Bow in Oklahoma 5-6 times per year they have 87 octane only. I usually have to put the boat on the trailer and take it to the gas station to get 93. The last time I filled up with 93 and ran in it down to half tank and then topped off the tank with 1/2 tank of marina gas which was 87. Hopefully the 87 1/2 tank + the 93 1/2 tank = 90 octane :confused: The boat ran fine surfing for the last 2 days and has every since then, but I have only put 87 in it that one time.

Not an issue with PCM...just saying.

[Amc0825]

I don't mind paying for the better fuel, just do not have access to it without taking the boat out of the slip.

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[sivs1]

loaded question. My first boat had the Volvo V6 and Out drive, said 87 in the manual. Ran 87 once and boat would diesel every time I turned it off. Ran 91 or better and it was fine. Have ran 91 or better ever since.

I am currently having an issue with my 13 SA with the LS3 motor, gas breaks down over time. I'm getting a bunch of mis-fire codes which all could be related to lower octane gas due to it breaking down.

[KnoxMojo]

E10 89 from the gas station. 5 gallon cans to fill on the lift. Most all newer high compression engines are going to the cooler burning octanes.

[MLA]

I don't mind paying for the better fuel,

Octane is not a quality indicator. Its a measure of its resistance to self ignite.


Most all newer high compression engines are going to the cooler burning octanes.

You're close. Once ignited, 87 and 93 have about the the same BTU's p/oz. The difference is that the 87 will ignite at a lower point then the 93. Higher compression engines have a higher combustion temp, so the we need a higher octane in order to resist pre-ignition.

Ethanol blended has a lower BTU and MPG then pure gas of the same octane. Thats why many notice a difference in fuel mileage between pure and E-10 gas.

[wario]

I’ve been told by two separate dealers selling indmar powered products that 87 is fine to run in the 400.

[larry_arizona]

I’ve been told by two separate dealers selling indmar powered products that 87 is fine to run in the 400.

As long as the ECM has high and low octane timing tables and utilizes Knock sensors to put it into the low octane timing table, I would agree.

Lower timing means reduced power but would be safe if 87 was all that was available.


E85 is badass in forced induction applications, it’s typically 100-105 octane. It’s truly race gas.

I have a 2010 CTSV with an LSA 6.2, E85 is amazing in supercharged engines.

But you need enough fuel pump to run it, flex fuel sensors and hybrid tuning for gas and E85 simply because E85 availability is still so limited. E50 seems to be the biggest bang for the buck (mix of 93 and E85 until flex sensor reads E50ish)

All said thought, E85 would suck for boats as it would draw so much moisture.





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[Broke Pilot]

All 89 gas is just a 50/50 87-93 mix done at the pump.
Worst case scenario just throw half 91 or 93 in there until you can get 89

[mikepo26]

i run 87 in my 08 lsv, everything newerish has a knock sensor so whatever you run it will retard timing if knock is detected

[Darter]

We use 89 as that's the lowest octane we can get without ethanol. Our local 87 has 10% ethanol.


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[AtTheRiver]

I run E10 87 octane all summer and will put the blue Stabil for ethanol every second or third time I top off gas. I rarely let it go below 1/2 tank. When the boating season is winding down, I will run whatever octane ethanol free gas I can get. Finding any ethanol free is a small challenge and some stations only carry 87 others 93.

The longer your ethanol based fuel sits around the more likely you will get phase separation and H20 in the gas so do not worry about it when I am filling the gas up every week or 2.

[DatTexasBoy]

93 all day.

[Kidder522]

I run 91 all the time.


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