Which fuel to use?

[airshot]

Make sure you guys look at the octane rating system called out in the requirements. RON vs MON vs R+M/2

Good point, but I havent saw anything except the R+M/2 method. How are the others used...metric ??

 

[88 Capri (2022 SOTY)]

Around here most use the 91 octane because it is non-ethanol and being my boat is an 88 I am sure it was designed for 87 but is there any other benefit to running the non-ethanol other than the longer shelf life? (what I have been told many times)

 

[dingbat]

Good point, but I havent saw anything except the R+M/2 method. How are the others used...metric ??

The research octane number (RON) describes the behavior of the fuel in the engine at lower temperatures and speeds, and is an attempt to simulate acceleration behavior.

The motor octane number (MON) describes the behavior of the fuel in the engine at high temperatures and speeds – a full-throttle range, comparable to driving fast on a highway.

 

[airshot]

The research octane number (RON) describes the behavior of the fuel in the engine at lower temperatures and speeds, and is an attempt to simulate acceleration behavior.

The motor octane number (MON) describes the behavior of the fuel in the engine at high temperatures and speeds – a full-throttle range, comparable to driving fast on a highway.

Thanks for the explanation, sounds a lot like government hoopla to make it sound important..lol..

 

[dingbat]

Thanks for the explanation, sounds a lot like government hoopla to make it sound important..lol..

Most the world, except US and Canada, uses RON

Pretty much a moot point anymore. Modern engines can adjust ignition timing to compensate.

 

[KD4UPL]

Around here most use the 91 octane because it is non-ethanol and being my boat is an 88 I am sure it was designed for 87 but is there any other benefit to running the non-ethanol other than the longer shelf life? (what I have been told many times)

Non ethanol has more energy than E10 so you will get better fuel mileage on non-ethanol.

 

[88 Capri (2022 SOTY)]

Cool, thank you.

 

[racerone]

Most vehicles do not need ---" full throttle "----to run at highway speeds.-----Look at videos of haulover inlet boats.-----50' boats with 4 outboards.----That is full throttle stuff.

 

[airshot]

Non ethanol has more energy than E10 so you will get better fuel mileage on non-ethanol.

I beg to differ, that is true on engines set up to run on different fuels. On engines set up to run strictly ethenol can produce more power than its gasoline cousin. Look at nascar engines, they are getting more power from E15 fuels than they ever got from straight gasoline. Unfortunately the mfgrs build engines to run on multi fuels, which actually makes the engine perform poorly on any fuel you use....again govt regs are running us backwards!!

 

[KD4UPL]

I beg to differ, that is true on engines set up to run on different fuels. On engines set up to run strictly ethenol can produce more power than its gasoline cousin. Look at nascar engines, they are getting more power from E15 fuels than they ever got from straight gasoline. Unfortunately the mfgrs build engines to run on multi fuels, which actually makes the engine perform poorly on any fuel you use....again govt regs are running us backwards!!

I didn't say anything about horsepower. I'm talking about the btu content of the fuel. There is simply more energy (btus) in a gallon of regular gas versus a gallon of E10. You probably can make more HP with E10 if the engine is set up right but you will use more fuel to do it. You can't just create energy.