which grade of fuel to use?

[ronskal]

Well as the proud owner of a new 210 (thanks all for your opinions etc. on that deal). I have read most of the literature. The PCM owners manual stated words to the effect that they recommend 87 but the engine may sense detonation/pre-ignition at that octane and 89 would prevent that.

OK, well then I run 89 just like my MC with the Indmar 5.7 said to do.

[gride300]

do not change the grade of fuel. stick with 87. you can use stabil as an every fill up additive if you want. it'll help keep some of the condensation out of the ethanol. you use far less than when using for storage.

[engkid_486]

just put some stabil in when you fill up with 87.

Is that necessary if you intend to go out consecutive days (refilling with fresh gas each day)? Is it incorrect to start off using 87 in the beginning (of weekend) and on the last day fill up using 89 (therefore some 89 is left in the tank for the 3 - 5 off days)?

[gride300]

just put some stabil in when you fill up with 87.

[engkid_486]

Ok.... So I did a search and answered my own question. All PCM (GM) after 2002 use 87 Octane Gasoline (Regular).

[engkid_486]

I am a Newbie as well to the Nautique family. Last week I recently purchased a 04 SANTE with the ZR6 6.0L powerplant. My question is also that the manual says "Most PCM Fuel Injected engines are calibrated to operate on 87 octane fuel and maximum performance is obtained when using this fuel. Some applications may require a higher octane fuel. These particular applications will be noted." Is it reccommeded for me to run 87 octane fuel in my Nautique?

[AirTool]

What a crock of crap ethanol is. There was a commercial I saw recently that Ethanol has created X number of jobs...... Yeah, fixing small engines that have gunked up carbs from this crap.
Sorry, just my .02

And fixing 2 stroke outboards with melted pistons.

Ethanol is for drinking and that's all. (Except in or around my boat - y'all know my rule on that.)

I saw a Food Network show the other night and there was a guy bragging on his clear plastic water bottles made from corn. I wanted to call and ask him if he knew that those green tractors in the corn fields burned diesel.

[shag]

I actually just ran a tank of regular non-ethanol gas in my Sierra (found it at a station near Mt Dora Florida, which is the only station in central Florida to carry it) and I got 17-18 mpg, as opposed to 13-14 mpg. Same type of driving, actually more start and stop driving on the Non-ethanol tank. What a crock of crap ethanol is. There was a commercial I saw recently that Ethanol has created X number of jobs...... Yeah, fixing small engines that have gunked up carbs from this crap.
Sorry, just my .02

[j2nh]

I'll echo what Scott said, in WI we can still get 100% gasoline, unfortunately it is 93 octane. I run it because it is pure gas, not because of the higher octane.

Government created this mess and like everything else once the government starts something there is no way to stop it.

[swc5150]

AT is correct. Most people don't have a choice, and have to run E10. We're fortunate in WI to still be able to buy 100% gasoline, although it's only sold as 93 octane - which is not necessary in these motors.

[AirTool]

I've read through this entire thread ...........

For your inboard,

Ethanol is ethyl alcohol.

E10 is okay in general. You won't have much choice otherwise.

Avoid E15 and never E85.

Avoid Seafoam for any use and it is expecially not a fuel stabilizer. It is modern snake oil for your engine and the only benefit is to the dealer and mfg that swiped 10 bucks out of your pocket.

[nordeast]

1984 SN confused about fuel

I've read through this entire thread and I'm still confused. I just bought a 1984 SN and right on the the gas cap it says not to use fuel that contains alcohol. Doesn't ethanol have alcohol in it? I have this boat up in the woods of WI and trailering to a gas station is a pain but trying to find regular gas may be real tough.

Do I have to run regular leaded gas in this or can I run ethanol in this boat without doing damage to it? If so should I be running a fuel stabilizer like seafoam in it (for moisture) or using a lead additive?

This is our first inboard and I just want to do right by my boat and try not to make any expensive boneheaded mistakes.

Thanks for the help,
Tony

[swc5150]

Ethanol is just another government "solution"... instead of simply drilling for our own oil, we're providing subsidies to turn our food/feed supplies into fuel. In WI, we can purchase both gasoline and E10, therefore I have first hand experience how subpar ethanol is. The average gas milage is reduced by 30%, which more than offsets the reduced price at the pump. I don't run ethanol in my boat, but I can tell almost instantly the performance difference ethanol makes if I use it my car. For every government action, there is an equal but opposite reaction. Sorry for the vent, but it is 3:15am here in beautiful WI! Drill baby drill!!

[shag]

Ethanol

Doesn't it actually cost more, and cause more pollution will all the manufacturing that it takes to make ethanol? My experience = before ethanol, no fuel problems in any equipment or engines. After ethanol, fuel related problems - mainly in small gas engines (lawn mowers, chainsaws, outboard motors, etc) but also have had problems in cars, and occasionally in my boats. (Fuel pump failure, fuel line de-lamination). Seems as though there is a correlation there.....

My .02

[DanielC]

I would use what the manufacture recommends, based on availability. I have a 1997 Ski Nautique, GT-40, recommended octane, 89, no ethanol. Here in Oregon, you cannot get ethanol free gas, and I have not been able to get it for several years, I run 89 octane E-10 gas. My manual does state, that if 89 is not available, you can run 87. The performance of the engine may suffer. I have experienced no problems with the E-10, my boat has over 2245 hours on it. I have also noticed that when I drain the FCC I rarely see any water.
I believe all GM engines since 2002 are set up to run 87 octane, and I think PCM has issued a recommendation that using E-10 is OK.

Before modern engines used computers to set the ignition timing, fuel grade choice was way more important. Engine knock, or detonation is very bad for a motor. A modern engine has a "knock sensor" on it that retards the ignition timing to prevent it. This is why a GT-40 may suffer a performance loss using a 87 octane fuel.

For all practical purposes, octane rating is a measure of how fast the fuel burns after the spark plug has fired. Higher octane fuels burn slower. A high compression engine typically will make the fuel burn faster, therefore they require a slower burning fuel to run right, without knock, a higher octane fuel.

If you run this high octane fuel in an engine designed to run a lower octane fuel, it burns slower, so the engine does not build maximum cylinder pressure at the same time in the combustion stroke, and you will lose power. It will not hurt anything, but you will use slightly more fuel than the lower octane fuel, and you will spend more money per gallon also.