No 87 Octane at Marina?

[jeeperman]

Re: No 87 Octane at Marina?

Same here. We actually got a mailing from our Yamaha dealer two years ago saying they were switching to premium fuel only at their pumps. Not becuase of the octane rating, simply becuase it's the only gas they could get without ethanol in it.

Ethanol is blended into the gasoline when the delivery truck to the station is filled.
It must have been a local terminal decision to only sell premium with the no ethanol option.

Just wait until 01-01-2011 when the only ethanol free gasoline available will be from marinas. Then watch the prices go up even more so.

 

[18WCmerc]

Re: No 87 Octane at Marina?

some quick insight, octane level refers to the resistance to detenation, in other words how volitile it is.

higher octane: is more difficult to combust, used for engine running at higher temperatures and higher compression ratios, keeps mixture from pre-detenating.

lower octanes: engines with lower compression ratios run on this, also a cooler running engine would run better too. canadian vehicles as an example. I tend to beleive that a boat engine runs cooler than a car. just because it is beat and runs harder doesnt mean its hotter.

a good example is diesel fuels, diesel fuels are 40 octane, it has to be very volitile because deisel uses its high compression and heat to combust its mixture with the lack of spark plugs (glow plugs only operate in colder weather depending on application/or just starting)

biggest misconception-higher octane = higher performance WRONG, however high performance needs higer octane, simply because of high compression ratios.

 

[haulnazz15]

Re: No 87 Octane at Marina?

had an old mechanic tell me, "the higher the octane the bigger the explosion in the cylinder, thus a better running engine"

Your mechanic doesn't understand what an octane rating is then. The explosion is no bigger for 91 octant than it is for 87. It is not more powerful in an of itself. The only thing that a higher octane fuel allows you to do is run a higher compression (or more advanced timing) without detonation. That being said, I run 91 octane in my boat just because the contant high load that a marine engine is subject to leaves less wiggle room on the detonation side. It doesn't give me any more power, nor is it "cleaner burning". The marinas at most of the lakes I know of only have 89 or 91 simply because a lot of go-fast boats require it due to the high compression engines or supercharged applications. The higher price at the marina is also mainly a product of supply and demand. Most marinas don't sell the same volume that a traditional gas station does, so they don't receive the same volume discounts. You are also paying a premium for not having to pull your boat out of the water to fuel up.

I always fuel up on the way out of town to get the cheaper price, but I don't go as far as to pull my boat back on the trailer just to save $10 in fuel cost.

 

[eclark53520]

Re: No 87 Octane at Marina?

i get laughed at for running super in our boat. it is a 1996 or newer 5.7 liter. and i buy gas at the local filling stations. in my mind , this motor is basically a 1960's -1970's car motor, no catalytic converteror,or other emission controls, etc... those cars all ran better on high octane gas.
maybe just my opinion. had an old mechanic tell me, "the higher the octane the bigger the explosion in the cylinder, thus a better running engine"

Google 'truth about octane' and read up.

There isn't any more power in higher octane fuel, it doesn't make a bigger explosion, it doesn't burn cleaner or faster. All myths. Calling 91 octane gas 'Super' or 'Premium' is purely a marketing scheme and nothing more. Since the majority of people refuse to educate themselves on what octane really is, those marketing schemes work and make the oil companies millions.

 

[dvandsm64]

Re: No 87 Octane at Marina?

o.k. maybe what i've always thought could be wrong. I also run super in my small engines: mower, weed eater, snow blower, etc... rarely have a problem starting any of them or them needing new plugs. dont know the compression of a 1996 0r newer 350 ci motor. in our boat.

 

[QC]

Re: No 87 Octane at Marina?

a good example is diesel fuels, diesel fuels are 40 octane, it has to be very volitile because deisel uses its high compression and heat to combust its mixture with the lack of spark plugs (glow plugs only operate in colder weather depending on application/or just starting

Do some more reading here . . . What you are quoting is actually Cetane and has very little in common with Octane or Knock prevention (detonation) or volatility. Confusing, but we don't really care about Octane with diesel as there is no fuel in the combustion chamber before we want it to burn. Stay tuned on that as we are working on something called HCCI (homogenous charge compression ignition). Problem is no one has figured out how to control it

Also diesel has lower volatility than gasoline. Anther semantics thing, but it has to do with how easily a fuel vaporizes . . .
Wikipedia:

Cetane number is actually a measure of a fuel's ignition delay; the time period between the start of injection and start of combustion (ignition) of the fuel. In a particular diesel engine, higher cetane fuels will have shorter ignition delay periods than lower cetane fuels. Cetane numbers are only used for the relatively light distillate diesel oils. For heavy (residual) fuel oil two other scales are used CCAI and CII.

 

[rbh]

Re: No 87 Octane at Marina?

Do some more reading here . . . What you are quoting is actually Cetane and has very little in common with Octane or Knock prevention (detonation) or volatility. Confusing, but we don't really care about Octane with diesel as there is no fuel in the combustion chamber before we want it to burn (stay tuned on that as we are working on something called HCCI (homogenous charge compression ignition. Problem is no one has figured out how to control it )

Also diesel has lower volatility than gasoline. Anther semantics thing, but it has to do with how easily a fuel vaporizes . . .
Wikipedia:

Cetane number is actually a measure of a fuel's ignition delay; the time period between the start of injection and start of combustion (ignition) of the fuel. In a particular diesel engine, higher cetane fuels will have shorter ignition delay periods than lower cetane fuels. Cetane numbers are only used for the relatively light distillate diesel oils. For heavy (residual) fuel oil two other scales are used CCAI and CII.

^^^^^^^^^

OUCh, head hurt, need more coffee.

 

[haulnazz15]

Re: No 87 Octane at Marina?

As far as volatility is concerned, think of it this way: if you have a cup full of gaoline and a cup full of diesel, you only have to hold a match over the cup of gasoline to have it ignite/explode. You practically have to touch the flame to the liquid diesel in order to make it catch; and it will just light a flame, it won't explode like gasoline does.

 

[JB]

Re: No 87 Octane at Marina?

Aside from mythology about "quallity" I see two practical reasons for a marina carrying only 89 and higher octane.

1. Almost any marine engine can run 89 or 93 without injury (except to one's wallet). But some I/O and inboard engines require premium and cannot run 87.

2. I have never seen a marina with three gas pumps. Years ago the two pumps carried premix 50:1 and premium gas. 50:1 was what most outboards wanted back then and premium didn't hurt engines back then, either. When premix went out of fashion they simply switched that pump to 89. Some marinas have a third pump for diesel.

 

[18WCmerc]

Re: No 87 Octane at Marina?

long story short, whatever the engine is labeled is what it gets.

 

[waterinthefuel]

Re: No 87 Octane at Marina?

My first post was obviously misinterpreted and I apologize.

Anything about gas or oil usually turns into a heated thread, and since that's where I was afraid this thread would end up, and being as how I've been here longer than most and seen it several times and considering in one of the handful of responses before mine someone already pointed out that you don't need high octane gas in an outboard and historically that's what sets it off, THAT'S what I was talking about when I said I didn't think this thread would have a happy ending. I was not bashing this thread, I simply asked a question.

 

['96 Charger]

Re: No 87 Octane at Marina?

All my cylinders are hitting between 120 and 125 psi on compression and my outboard is rated for 86 octane. Since there's still usually several gallons in the tank to degrade when filling up should I go ahead and get premium ethanol free? I can already tell you the throttle response is better with premium and so is the drain on my bank account...but a rebuild still costs a fortune even if I do have someone that will do it for the price of parts and little more. Did I just answer my own question like the op? No I'm not being a smart one either. Just ONE octane point isn't much wiggle room at all.

As for the 1-1-11 thing where all land based station will have shine mixed with the gas, is this for all states? My local marina sells e-10 and the station close to it that sells pure petroleum won't convert without a fight. The old man that owns it seems to really care about selling gas that won't tear up everything that it goes into.

 

[Shrike]

Re: No 87 Octane at Marina?

More compression calls for more octane.
Less compression less octane.
If you are using higher octane than your engine needs you are wasting money.