Fuel grade

[rb8484]

Hey everyone
Had a question on a boat that im looking at. It is the 5.7 mercruiser alpha one and was wondering what fuel should be run in it.

My first boat was a 28' pontoon
My second boat was a 16' four winns I/O with the little 4 banger in it and run 87 oct.

So what is recommened for this boat im looking at??

 

[Bondo]

Re: Fuel grade

Ayuh,... Same gas...

 

[rb8484]

Re: Fuel grade

Ayuh,... Same gas...

Thanks! Someone told me premium, so i wanted to ask!!

 

[5150abf]

Re: Fuel grade

Ya, unless you have that built to the hilt regular unleaded is fine, if your freind want to spend the extra money for nothing I geuss that is his deal.

In a regular engine higher octane doesn't do anything, some of it has more additives but it doesn't burn different or give you any more power.

Octane rating is the fuels resistance to detonation or "knock" so if your engine doesn't knock the extra octane just drains your wallet faster.

 

[HOLYSMOKES]

Re: Fuel grade

Hmmmm. I was told that the HIGHER octanes actually burn COOLER than 87. I will have to investigate to see if there is any truth to it.

 

[HOLYSMOKES]

Re: Fuel grade

Appears that ETHANOL in the fuels are KILLING motors. Funny twist. Merc will warrany motors with 10% or less E fuel mixtures....may 14,2009, accorcing to washington post, government wants to bump the E rating in fuel from 10% to 15%. Looks as if the Merc mechanics will be busy voiding warrantys.

 

[5150abf]

Re: Fuel grade

It may, my point was everyone seems to think that you magiclly gain a bunch of horse power when you fill up with premium and that just isn't the case.

There is a guy at work that insists on buying premium for a Dodge pick up, I can't imagione how much money he has wasted but he thinks it runs better and it is his wallet so have at it I geuss.

I knew another guy that raced amatuer moto cross and he would buy racing gas, mix a couple gallons for practice and DUMP what was left and mix new because it "went bad".

I tried to explain that gas doesn't go bad in an hour or two but again he was right and no one was going to change his mind, people are funny.

 

[TilliamWe]

Re: Fuel grade

Appears that ETHANOL in the fuels are KILLING motors...

Appearances can be deceiving.

No need for premium fuel in any Mercruiser engine, that I am aware of. 87 octane will do the trick, quite nicely. And don't worry about 10% ethanol, it's been around for a long time, and it doesn't cause nearly as many problems as people think or as they are blaming on it.

 

[rb8484]

Re: Fuel grade

Thanks for all the input on this. I didnt think there was a need for higher octane gas, but wanted to double check!!
Thanks!

 

[Maclin]

Re: Fuel grade

Some of the confusion comes from the rating method for octane levels. The method used here in the states ((R+M)/2) will show a lower number than methods used in Europe and other countries (RON) for the same levels. Some engine manuals show the RON method and say you need 93, the (R+M)/2 method number wouild be 87 and it is the same level of octane. Some show both methods, and you will see the 87 number there.

 

[Maclin]

Re: Fuel grade

I am not a chemist but I worked for a refinery for a while, octane enhancement is the last step! So, doing the "math" all grades of gasoline are literally the same.

 

[Sikiguya]

Re: Fuel grade

May still want to use ethanol treatment on your gas.

 

[Varago]

Re: Fuel grade

FYI VP states in there 08 operators manual.
"If fuels with 89 AKI or higher are used an INCREASE in power can expected"
on page 80 under galoline recommendataions. If seems the EFI engines use a knock sensor and will adjust the timing to the gas. In engineering we have an old saying RTFM.

Dave

ps not so very long ago a very nice person I worked with was talking to the people that made the saftey stickers for us and they ask if there was anything they could make for him, samples wise.

So this is what we got back

RTFM
Failure to do so will result in loss of gene pool privileges.