Fuel-high octane vs. low octane

[dpfishin1]

>What grade fuel do you run
>through your motor? I've
>heard those who run a
>low octane fuel called idiots
>by those who only run
>high octane fuel. But
>I have also heard that
>high octane fuel is not
>necessary and can damage your
>motor. What do you
>guys think?

I HAVE 96 EVINRUDE 200 VINDICATOR. I RUN 87 OCTANE, BUT I ALSO RUN STABILIZER YEAR AROUND. NEVER HAD ANY PROBLEMS.

[LAWNMAN]

low octane fuel ,when it is ignighted has has a slower burn to it so the fire last longer and that makes more heat compared to higher octane that burns faster,so there is less heat, that makes your engine run cooler, that is why they will perform better. i dont know about the cumputers and if they can tell the differences in octane . the carb run engines are better off with high octane. and good oil.and cold plugs. my thoughts... jon hoover

[BillDay]

High octane burns SLOWER than low octane fuel. The reason currnet manufacturers advise the user to go with lower octane fuels is to REDUCE cabon buildup, a by product of combustion. Low octane fuel burns faster and more complete than high octane fuel, therefore there is less carbon build up. The engines today are "mapped" to use the low octane fuel. if you use high octane on a stock engine, you will get carbon buildup which can lead to engine failure after extended use.
Bill Day

[Richman]

My 2 cents....burn what the manufacturer recommends. I run a 10 year old Merc 150 XRI on 87 octane. It runs great and does what I need it to do. Never a problem with it.

Good luck

Rich

[gcgar]

i've got an older motor, '87 was told by mechanic to run high octane. when i use 87 octane my boat won't hardly run. really sluggish. was told with older models it was recommended to run higher octane

[90skeeter]

i have a 90 merc 175 and was told that lower grade is good enough too run in it ,but i should buy it from the better gas stations and not just go with whoever is cheaper

[Chefdave]

I have a 95 Evinrude 225 Vindicator. All of the professional marine mechanics I have spoken with say high octane is best. I only use Chevron with Techron. From what I have been told, Not only does the H/O burn quicker and cooler but also cleaner.
I always run fuel additive (Ring Free). In the past, I have run lower octane, and had problems, especially carbon buildup. Also from what I have read, The real problem with fuel and outboards these days is RFG gas which is said to corrode rubber fuel lines and parts.
Of course What the heck do I know.
Just my 2 cents
Chefdave