New 4.3 MPI, which of these fuels would you choose?

[mytiburon]

I have a new Chap 19 H20 with 4.3 MPI on the way, The boat will sit for periods of up to two weeks at a time before it gets used. Anyways our fuel options are 87 with 10% ethanol or 91 with 0% ethanol which cost an extra .45 cents a gallon, any suggestions on wht would be better for this engine. Thanks.

Before I forget, would it be wise to invest in a mercmoniter guage, if you have one in a bowrider how do you like it. Thanks all.

 

[MarkSee]

Re: New 4.3 MPI, which of these fuels would you choose?

Welcome to IBOATS

Two weeks is not all that long at all. I'm also not a believer in "always keeping your tank filled to the max to help keep out water".

I'm sure someone might be able to define "better" but both in my 4.3 and 7.4 I use 87 along with a fuel additive that either Mercury/Quicksilver or Sta-bil makes to help with the ethanol.
1 ounce for every 10 gallons of gas and change the water separating fuel filter regularly and should not have any problems.

Mark

 

[tazrig]

Re: New 4.3 MPI, which of these fuels would you choose?

Believe you should be running 87 octane per the manufacturer. Always go with the manual.

Just curious, where are you located that you can get 10% ethanol?

 

[HT32BSX115]

Re: New 4.3 MPI, which of these fuels would you choose?

I have a new Chap 19 H20 with 4.3 MPI on the way, The boat will sit for periods of up to two weeks at a time before it gets used. Anyways our fuel options are 87 with 10% ethanol or 91 with 0% ethanol which cost an extra .45 cents a gallon, any suggestions on wht would be better for this engine. Thanks.

Before I forget, would it be wise to invest in a mercmoniter guage, if you have one in a bowrider how do you like it. Thanks all.

Howdy,

Welcome aboard!


You're fine with letting it sit for for that long with any fuel in the tank. That Mercmonitor is pretty neat. I would want one just for the fuel used/fuel flow and GPS speed etc.

Pricy though.

I'm also not a believer in "always keeping your tank filled to the max to help keep out water".

Yeah, me neither, and I agree with this guy: The Myth of Condensation in Fuel Tanks by David Pascoe: Boat Maintenance, Repairs and Troubleshooting


Cheers,


Rick

 

[mytiburon]

Re: New 4.3 MPI, which of these fuels would you choose?

Great Feedback, I am in Saskatchewan, therfore all regular is up to 10% ethanol,mid grade up to 5% if you can find it and premium is none. I will stick with the cheap stuff and additive! I look forward to being a biggert part of the community especially once i get some hours logged

 

[QC]

Re: New 4.3 MPI, which of these fuels would you choose?

The only reason I would be concerned about the 10% ethanol is a tendency to vapor lock in high ambient conditions. That does not seem to be an issue for you, so the 87 should be perfect.