regular or super unleaded

[Joshua Nichols]

Was just wondering if yall run premium or regular unleaded in your tubs.. I use to run the super stuff in my outboard.. With my I/O I have been running regular.. Just wanta see whats the way to go..

 

[sethjon]

Re: regular or super unleaded

Was just wondering if yall run premium or regular unleaded in your tubs.. I use to run the super stuff in my outboard.. With my I/O I have been running regular.. Just wanta see whats the way to go..

If you're runnin' ok then you're good to go. At best you might need 89 but not the hi stuff.

 

[BaileysBoat]

Re: regular or super unleaded

Regular Shell unleaded during the season, Shell V power premium the last few tanks before winter layup. Reason being the premium is ethanol free, at least here in Ontario it is.

 

[paultjohnson]

Re: regular or super unleaded

Regular Shell unleaded during the season, Shell V power premium the last few tanks before winter layup. Reason being the premium is ethanol free, at least here in Ontario it is.

X2 good advice

 

[6meter]

Re: regular or super unleaded

89 is what they have at all the marinas around me.

 

[dvandsm64]

Re: regular or super unleaded

i run super e10. but everyone laughs at me for buying super

 

[dubs283]

Re: regular or super unleaded

best bet is to run a premuim, non-oxy gasoline

you don't want to be running ethanol blended gasoline, the alcohol attracts water and can cause major headaches - also can lead to vapor lock on hot days

 

[Brewman61]

Re: regular or super unleaded

I run the marina's gas- 92 octane, no ethanol. They don't offer any 87 or blend grade. My motor is designed to run on 87 octane, and I've done it with absolutely no problems- but I'd have to haul out or bring in if I wanted it, simply not worth the bother for me. Not having the alcohol in the gas is fine by me as well. One less thing I have to worry about.

 

[Rocky_Road]

Re: regular or super unleaded

My engine calls for 87 octane...but I run 89 octane, since E-10 loses octane faster than the old 'straight' gas!

Happy boating!

 

[NHGuy]

Re: regular or super unleaded

My lake has 89 octane, my compression ratio is correct for 89 octane, Mercruiser says 87 is OK. I use 89. Ain't no knock sensors on 1988 5.7 motors.

 

[wanna-be]

Re: regular or super unleaded

the super stuff may fire a lttile late. not always the best for water sports. 87 is ok but you can't hear the knocking with wind and engine running and its a little sluggish with a load. so i mix 87 and 93, 50-50 to get 90. does very well for water sports. but if im just cruising or fishing i'll fill up on 87. my '91 5.7 isn't made for premium.

 

[scooper77515]

Re: regular or super unleaded

I originally ran regular in my volvo, but it had that dieseling on the first tank. It didn't bother me much, but the wife hated it, and it could have been embarrassing with a couple of passengers on board.

2nd tank has been premium, and still runs great, and no more dieseling.

I get 4 trips per tank, plus or minus, so spending $50 on a tank of super is worth it to me, since my engine seems to want it.

It is not helping or hindering performance, just cutting out that dieseling.

 

[The Dougler]

Re: regular or super unleaded

Shell V-power soley because it is Ethanol free. I have snuck a few tanks of regular through when i know I'm going to burn through most of the tank in a short time period. But if it's going to be sitting awhile then it's V-power.

 

[wired1236]

Re: regular or super unleaded

I originally ran regular in my volvo, but it had that dieseling on the first tank. It didn't bother me much, but the wife hated it, and it could have been embarrassing with a couple of passengers on board.

2nd tank has been premium, and still runs great, and no more dieseling.

I get 4 trips per tank, plus or minus, so spending $50 on a tank of super is worth it to me, since my engine seems to want it.

It is not helping or hindering performance, just cutting out that dieseling.

Dido...except the wife could care less. I care since it can suck water back into your engine.

 

[LazyCruiser]

Re: regular or super unleaded

My marina has 87, but my 'master plan' will be to pull out once in a while to fill up on land with 89.
And I also use Marine Stabil, no matter what grade.

 

[89mercruiser]

Re: regular or super unleaded

On our 89 3.0 alpha 1. We run 89, manual says 87 is ok but our mechanic said use 89 or higher.

 

[scipper77]

Re: regular or super unleaded

This is all hearsay but I read somewhere that during storage ethanol gas can lose octane rating having something to do with ethanol having very high octane, and the octane rating of e-10 being an average of gas and ethanol's octane.

I really can't substantiate any of this but maybe someone else can.

My point is that if this is true there may be a benefit to using super for storage periods.

 

[bruceb58]

Re: regular or super unleaded

Since one of the properties of ethanol is to boost the octane rating of the gasoline, ethanol that evaporates will reduce the octane of the gasoline. That being said, not sure how much ethanol will actually evaporate stored over the winter. Probably negligible.

 

[HT32BSX115]

Re: regular or super unleaded

This is all hearsay but I read somewhere that during storage ethanol gas can lose octane rating having something to do with ethanol having very high octane, and the octane rating of e-10 being an average of gas and ethanol's octane.

Yeah, it is "hearsay"

Actually older blends of (non-ethanol blends) gasoline (and winter grades etc) will "lose" octane when stored over long periods of time because the "higher ends" DO evaporate overtime. (summer gasolines are made with lower vapor pressure than "winter " gas)

The older blends did it more readily because the EPA allowed refiners to manufacture gasoline with higher vapor pressure "back then".

Over the last several years gasoline refiners have been mandated to make gasoline with lower vapor pressure to reduce evaporation (and reduce "evaporative-emissions")

Aviation gasoline for example, has ALWAYS been made with an RVP (Reid Vapor Pressure) of about 7psi. (this is because gasoline can actually boil at high altitudes causing vapor-lock and engine failure in aircraft)


RVP in Calif back in the early 1990's could be as high as 9psi.

It's now limited to around 7psi ( http://www.arb.ca.gov/fuels/gasoline/rvp/rvp.htm )

Low RVP gasoline can be a problem in carbureted engines because it doesn't vaporize as well as gas with a higher RVP. (it doesn't matter as much in in an EFI engine because you have a pressurized fuel injector to atomize the fuel)


None this matters anymore though since refiners are completely controlled by the EPA and for gas used in Calif, the EPA and CARB (California Air Resources Board)

Don't always assume that because the retail gas station "says" you're getting NON-oxygenated fuel that you're actually getting it! It may still contain ethanol!


If you want to be absolutely sure that you're getting gas without alcohol in it, you'll have to test it using one of the many kits available (to buy or one you make)


Now, having said all the above.... I have used E10 (regular) in my boat for as long as I have had it and cannot tell any difference from any other grade......



ymmv.......

 

[scipper77]

Re: regular or super unleaded

That being said, not sure how much ethanol will actually evaporate stored over the winter. Probably negligible.

I was actually thinking about the effect of ethanol pulling moisture out of the atmosphere. Not just evaporation.

Having said that, I am no fuel expert and don't want to perpetuate any false information. I just wanted to discuss this so we all can learn the facts.

All loss of octane issues aside, my boat says 87 octane, I use 89 even though I logically know there is no benefit to spending more for 89.