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Akor from your posts you seem pretty savvy when it comes to mechanical knowledge, so I hope I'm not speaking out of my hind end here...

I have a buddy that is a small engine mechanic on the side. He has shown me what happens with ethanol and how it absorbs moisture in the air. After a few days the polymers look like little yellow burgers, and that is what clogs filters and screens. So even a motor that is designed to run on the stuff with compliant O rings, gaskets and hoses, it will gunk up an engine. Fuel filters help obviously, but the stuff gunks up in the lines between the filter and throttle body somehow. I'll drive across town to get Non Ethanol fuel if I have a choice.

When I'm on road trips I used to always fill with premium if there isn't an alternative, but not so much anymore, because in any other state beside here there a good possibility of premium having at least 10%. I dont worry too much about it, especially if I'm going to be burning it up. Mileage suffers, but the stuff isnt going to be in the tank long enough to make a difference in absorbing any moisture.

One of the engineers in Ponca City Ok (where ConocoPhillips has a huge gas refinery) told me to always buy Conoco premium if I wasn't sure. Some refineries blend ethanol into their premium to increase the octane, so it really depends on what State your in and which refinery your gas came from. In Oklahoma he have a huge rate of Non-Ethanol stations,usually with large banners or signs advertising straight gas.

Ytmsn wrote: Tue May 07, 2019 7:28 am Akor from your posts you seem pretty savvy when it comes to mechanical knowledge, so I hope I'm not speaking out of my hind end here...

I have a buddy that is a small engine mechanic on the side. He has shown me what happens with ethanol and how it absorbs moisture in the air. After a few days the polymers look like little yellow burgers, and that is what clogs filters and screens. So even a motor that is designed to run on the stuff with compliant O rings, gaskets and hoses, it will gunk up an engine. Fuel filters help obviously, but the stuff gunks up in the lines between the filter and throttle body somehow. I'll drive across town to get Non Ethanol fuel if I have a choice.

When I'm on road trips I used to always fill with premium if there isn't an alternative, but not so much anymore, because in any other state beside here there a good possibility of premium having at least 10%. I dont worry too much about it, especially if I'm going to be burning it up. Mileage suffers, but the stuff isnt going to be in the tank long enough to make a difference in absorbing any moisture.

One of the engineers in Ponca City Ok (where ConocoPhillips has a huge gas refinery) told me to always buy Conoco premium if I wasn't sure. Some refineries blend ethanol into their premium to increase the octane, so it really depends on what State your in and which refinery your gas came from. In Oklahoma he have a huge rate of Non-Ethanol stations,usually with large banners or signs advertising straight gas.

Ytmsn; Thank you for the feed back. Where I live in the Hill Country of Texas it appears the closest non ethanol fuel is about 2.5 hours round trip . This does make obtaining non ethanol fuel difficult which is why I initially though of using avgas, which I now understand is not really an option.

That sucks. I guess using the blue stabil or merc additive is going to be your friend.

Ytmsn wrote: Tue May 07, 2019 7:28 am Akor from your posts you seem pretty savvy when it comes to mechanical knowledge, so I hope I'm not speaking out of my hind end here...

I have a buddy that is a small engine mechanic on the side. He has shown me what happens with ethanol and how it absorbs moisture in the air. After a few days the polymers look like little yellow burgers, and that is what clogs filters and screens. So even a motor that is designed to run on the stuff with compliant O rings, gaskets and hoses, it will gunk up an engine. Fuel filters help obviously, but the stuff gunks up in the lines between the filter and throttle body somehow. I'll drive across town to get Non Ethanol fuel if I have a choice.

When I'm on road trips I used to always fill with premium if there isn't an alternative, but not so much anymore, because in any other state beside here there a good possibility of premium having at least 10%. I dont worry too much about it, especially if I'm going to be burning it up. Mileage suffers, but the stuff isnt going to be in the tank long enough to make a difference in absorbing any moisture.

One of the engineers in Ponca City Ok (where ConocoPhillips has a huge gas refinery) told me to always buy Conoco premium if I wasn't sure. Some refineries blend ethanol into their premium to increase the octane, so it really depends on what State your in and which refinery your gas came from. In Oklahoma he have a huge rate of Non-Ethanol stations,usually with large banners or signs advertising straight gas.

I'm not an SAE mechanic, but I've been turning wrenches since before I could walk, building track cars, hotrods, mud trucks, motorcycles, pretty much anything that runs on gas and I can 'improve', lol. You make two very good points,

1) Ethanol fuel is really only an issue if it sits, which is when it absorbs moisture and clogs small orifices, and why we stabilize our fuel for storage. Even then, more than a few months and the fuel becomes questionable.

2) typically even premium has at least 10% ethanol blend, which is why you always want to fill up at high volume gas stations where fresh fuel is always available.

That said, any engine designed after the late-90's will be 'ethanol safe' which just means the materials in the fuel system are tolerant of alcohol. While WI has a decent amount of straight gas stations, none are convenient for me on a regular basis, and I drive ~30k miles/yr just commuting to work, so convenience is important. I've never had an issue running ethanol gas in any of my engines aside from small engines. For some reason small engine manufacturers were much slower to adopt E-safe fuel systems, which is why I have to clean the carb on my lawnmower and power washer every spring, even with treated fuel. Anything fuel injected, aside from my old school Holly Pro-jection on my Chevelle, has been totally fine on normal old pump gas.

Ethanol isn't a terrible thing. If it were more readily available it actually makes more power than traditional blended gas, and the fuel system needs to be designed for it both in material, and volume it can move. I have friends that run straight corn juice on boosted BMWs making 4 figure power numbers.

Marine manufactures were a bit behind adapting to ethanol as well, maybe because you could get straight gas on the water more readily than the road. Even now there are a few Valvetech fuel stations on the Chain that sells non-ethanol mid-grade and premium. But by the early 2000's I can't think of a manufacturer that wasn't designing for ethanol.

Thanks for the info... Like me my information related to ethanol and engines is old...

My experience mirrors that of akorcovelos and Ytmsn - ethanol isn't a huge problem in a daily driver other than maybe losing a tiny bit of mileage per gallon, but in small engines that sit most of the year without running (snowblower, mower, generator, pressure washer, etc.), I now only use nonoxygenated fuel and add some sta-bil at the end of the season, and often some seafoam at the beginning of the next season just to keep from spending all my time rebuilding small engine carburetors.

Some of the Volvo Pentas that run just fine on 87 octane can advance timing slightly if fed 89 octane, but anything higher than that with most engines and you're wasting money. Your engine manual should have the details.

John

jhnmdahl wrote: Tue May 07, 2019 5:07 pm My experience mirrors that of akorcovelos and Ytmsn - ethanol isn't a huge problem in a daily driver other than maybe losing a tiny bit of mileage per gallon, but in small engines that sit most of the year without running (snowblower, mower, generator, pressure washer, etc.), I now only use nonoxygenated fuel and add some sta-bil at the end of the season, and often some seafoam at the beginning of the next season just to keep from spending all my time rebuilding small engine carburetors.

Some of the Volvo Pentas that run just fine on 87 octane can advance timing slightly if fed 89 octane, but anything higher than that with most engines and you're wasting money. Your engine manual should have the details.

John

Sadly, when I bought my boat, NO manuals were included.

Go here for owners manual and sales brochures: http://www.cobaltboats.com/owner/resources/

jhnmdahl wrote: Mon May 06, 2019 9:16 pm I’ve used Sierra filters, but get that for a few bucks more many don’t want to stray from Volvo branded stuff. And I’ve always had good luck with NGK or Bosch for plugs, and I’ve been using NGK TR5IX in my boat. Mobil 1 from Walmart is good, cheap oil.

John

What weight oil are you using?

pcarp,from my notes, Volvo recommends at least 30 weight or higher for my engine, with no 0W-30. Given marine engines are under a fair amount of continuous stress relative to car engines, I went with Mobil 1 15w/50. I change at end of season for clean, dry oil over winter, and it takes 5.5 quarts (Volvo says change every 100 hours). According to my notes, Mobil's 15w-50 has 1200ppm phosphorous and 1300ppm zinc (high zddp), which is probably why I leaned toward this particular heavier oil in selecting. Plus, it's cheap in the five quart jugs at Walmart

John

jhnmdahl wrote: Thu May 09, 2019 9:05 pm pcarp,from my notes, Volvo recommends at least 30 weight or higher for my engine, with no 0W-30. Given marine engines are under a fair amount of continuous stress relative to car engines, I went with Mobil 1 15w/50. I change at end of season for clean, dry oil over winter, and it takes 5.5 quarts (Volvo says change every 100 hours). According to my notes, Mobil's 15w-50 has 1200ppm phosphorous and 1300ppm zinc (high zddp), which is probably why I leaned toward this particular heavier oil in selecting. Plus, it's cheap in the five quart jugs at Walmart

John

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+1

Good oil discussion here.

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I've always run Delo diesel oil in my boats with good success, but oil can be debated until the world ends and nobody will agree on the 'right' oil.

akorcovelos wrote: Fri May 10, 2019 7:06 am I've always run Delo diesel oil in my boats with good success, but oil can be debated until the world ends and nobody will agree on the 'right' oil.

so true.
And considering we hold on to mfg beliefs of what was recommended 20 years ago ,and we add new technologies that mfg recommend today ( syn blends and full) it’s gets more spread out.

Diesel oil detergents are superior in the ability to trap contamination and moisture. A lot of Marine service facilities use it. It’s a good one

Thank you for the insight on engine oil, I will go that direction (15 w 50) for the next oil change.