Type of gasoline?

[bp21]

local wrench told me it was OK to run premium grade in my '98 90hp Evinrude. I was always under the impression that regular was the best. Will running premium hurt my engine?

 

[hunt-fish.com]

Re: Type of gasoline?

I've run super unleaded in my motors until the price went out of sight. I can't tell the difference. Look at the manual and go by the spec for the octane rating.

 

[Walter]

Re: Type of gasoline?

Higher octane = greater anti-knock additives. Your Evinrude doesn't need that...it will run fine on 87 octane. <br /><br />Walt

 

[Dhadley]

Re: Type of gasoline?

The difference is in the exhaust gas temps. With stock compression ratios stick with the FRESH 87 octane and Champion plugs.<br /><br />Good luck!

 

[kevlar3000]

Re: Type of gasoline?

I live in a city that has oxygenated fuel. (Ethanol) I was told by Grubbs Marine, many of you kind wrenches here , boat classics.com, and my local Merc dealer to run on 91 non oxygenated fuels that are available at a few stations in the Minneapolis area. If you are in an ethanol area your fuel needs may be different. The ethanol blend here is 7 to 10 percent.

 

[JB]

Re: Type of gasoline?

Howdy, Kevlar. The reason for avoiding alcohols is that many engines have materials in the fuel system that are adversely affected by alcohols; they soften, swell or even melt.<br /><br />Other, oxygenating additives may be just as bad and I would avoid them if possible. Using 91 octane that does not have those additives is an option.<br /><br />Were I still living in the Minnie-hopeless area I would check the fuel available in outlying communities or towns on the way to Leech, Cass, LOTW or where ever I was muskie hunting that week. It is my understanding that extremely modified gasoline is only mandatory in metro areas but rural locales can still sell the simpler stuff. I certainly get better gas, cheaper, out here in the stix than in Fort Wuthless.<br /><br />Red sky at night. . . <br />JB

 

[kevlar3000]

Re: Type of gasoline?

Hey JB,<br /><br />They love their corn here in the heartland. They love their corn even more if they can sell it in state for ethanol. It is all over the state, from Duluth, to Ely, to Fergus Falls, to..... It is now all over, I have to use the stuff that the classic cars use. Unless you have a boat or a classic car you can't but it. I am lucky as one of the few stations in the metro that has it is a few blocks from the homestead. Now, I have always referred to it as Minnehopeful.... I let the people in Doomington, St Drunk, Brooklyn Sucker, and Detroit Lacks, deal with the crap....

 

[yensid]

Re: Type of gasoline?

kevlar, just curious where you're buying the non-alcohol gas? I live in the same area....

 

[JB Cornwell]

Re: Type of gasoline?

There was a statement in an otherwise superb article posted into the "New Boater" topic this AM that warns against using 87 octane unleaded in boats.<br /><br />IT IS NONSENSE.<br /><br />Take the advice of the working (and retired) wrenches, engineers and other experts on this board. If we do it wrong, it costs us.

 

[JB]

Re: Type of gasoline?

Yes that's me. I re-registered by mistake. I'm back to my original registration now.<br /><br />Red sky at night. . . <br />JB

 

[kevlar3000]

Re: Type of gasoline?

Hi Yensid,<br /><br />I searched online for non oxygenated fuels. I was able to download a list for MN gas stations. Use google as your search engine.

 

[yensid]

Re: Type of gasoline?

:blush:<br /><br />I usually do that first. Thanks, Kevlar3000....

 

[yensid]

Re: Type of gasoline?

Excellent! There's one right by my house! <br /><br />Interesting thing, non-ethanol gas is only available in premium. Hmmm...I'm thinking being alcohol free is better. What do you think, JB?

 

[Diesel]

Re: Type of gasoline?

Here on Vancouver Island the majority of "marine" marked fuel is mid grade unleaded, 89 octane. Pretty much what most of us run up here, seems to work just fine. Our regular car fuel is 86.

 

[JB]

Re: Type of gasoline?

Yes, Yensid, I agree with you. Alcohol free mid-grade or even premium would be better than gasohol for 2 strokes and older engines.<br /><br />I noticed a note in the Manual for my new Suzi 4 stroke. It says gasohol is okay. I wonder how many new engines can use it. My engine, of course, has been in autos for years in a slightly different form and doesn't mix fuel and oil.<br /><br />Way back, when I was racing and used methanol/nitro/ether for fuel I had to use synthetic oils (or castor oil) because the fuel would not mix with petro oils. That could be another issue with non DFI 2 strokes, maybe petro base oils will not stay mixed with gasohol even if the rest of the system is tolerant of it. Any ideas on that??<br /><br />Red sky at night. . . <br />JB

 

[kevlar3000]

Re: Type of gasoline?

never and i mean never, eat yellow snow!!

 

[kevlar3000]

Re: Type of gasoline?

i was so caught up in my quote that I forgot to reply!!! lol<br /><br />Yensid, the only formulation of non ethanol in MN is 91 octane. I looked for other options as well, but the boat has ran great all season. I was lucky too, have a station 5 blocks away with non oxy gas.

 

[Down South]

Re: Type of gasoline?

Hi bp21,<br />I'm a mechanic, Been one for 30 years now. Use you manufactures recommendations. I'm sure they recommend regular unleaded gas. There are good reasons for this. The motor was designed to run with a specific grade fuel.

 

[kevlar3000]

Re: Type of gasoline?

merc book recommends 89 octane. Grubbs Marine as well (oldmercs.com) but it does not consider the ethanol additive. That is a midwest fuel issue. So locally the Mechanics<br />are saying use non oxy, as well as numerous internet sources I have contacted. Oldmercs. Boatclassics. Iboats. Screamandfly....ect...I find it such an interesting controversy.... Even for something as logical as an engine there are still tons of different opinions.

 

[grandx]

Re: Type of gasoline?

OK guys, Alcohol is no good for many plastic and rubber components in your fuel system, no good for many cars either everyone should understand this, if running alcohol make sure fuel system was designed for it. <br /><br /> For this thread, I am only interested in OCTANE. I'm sure it has ben discussed to death, as there are many opinions on the subject. Here's what I think I know, please feel free to shoot holes in it or support it.<br /><br />1. Generally speaking, the higher compression engines need higher octane to prevent pre ignition.<br />2. If you have low or lower compression you probably do not need higher octane fuels. Octane suppresses ignition until spark.<br />3. Engines that require higher octane will knock or ping, may be difficult to hear with noisy 2 strokes.<br />4. An older engine that has performed fine for years on 87 octane, may get carbon build up, sticky rings etc and increase the compression, and now require a higher octane??? <br /><br /><br />I think I'm clear on the potential danger of running too low octane in an engine that needs it. What's the danger of running higher octane in one that does not need it?<br />outside of going broke?<br /><br />Have at it everyone.<br /><br />dg