There was a post about Vmax 150s yesterday. I noted that I put premium in my tanks but someone else mentioned that it burned too hot and could blow a head. What are halls thoughts? I thought premium was just cleaner and burned better. Should I stick with regular and just keep adding the Stabil?

That motor doesn't require higher octane for the compression ratio, so it is best to run regular in it.

Yes, regular gas and a fuel additive like stabil or ring free etc.

My boat mechanic has always told me the same thing, higher octane burns hotter which is not a good thing in outboard engines.

If the engine doesn't specify that you need to use a higher octane, then don't.

Get fuel from busy stations (this helps ensure that the fuel is fresh) and put some kind of stabilizer in each tank and you'll be fine, and save a lot of money.

Higher octane DOES NOT burn hotter, that is false information, but your motor is designed to run on regular fuel so use that along with additives like those suggested above.

Your mechanic is FOS, Matt. Higher octane does not burn "hotter". High-octane fuel is needed for higher compression ratios in high performance engines. My SHO calls for 89 octane which is a real PITA because very few stations outside the city carry it. So I have to use 50/50 regular/super most of the time.

Huh? I've seen 89 octane at almost every gas station I've ever been to. Rural or not.

Most around Fork that I have visited have regular and premium. Some have only regular.

That would be the first time my guy has ever been wrong!

The guys above are correct. Higher octane means it ignites slower. Keeps the engine from having preignition from higher compression ratios. Premium fuel does tend to carbon up engines that are designed to run on regular. A carboned up engine can run hotter than normal.

I have a '98 Champion with a '98 Merc. 175 H.P. EFI I bought it used in '99 from a guy who told me he used premium gas in it. I have been using premium with fuel stabilizers since then and have had zero problems with it. Only replaced the hoses once in that time as well due to the deterioration caused to them by the unleaded fuel.

Octane has absolutely nothing to do with how hot it burns. The air/fuel ratio, ignition timing and several other factors determine the heat of combustion.

Octane is merely the fuels measured ability to resist detonation.

Robert Lane
Fast Lane Nitrous Racing Systems
http://www.fastlanenitrous.com

Just put super unleaded in it. That will not hurt anything. Just gives a little more detonation resistance. And costs a little more.

No no no no. True story: The other day I stopped by a gas station owned and operated by a middle eastern fellow. They were out of regular unleaded but he said its OK because the premium gets better gas mileage so the extra cost will pay for itself. Now if you have a higher performance(higher compression) engine that SPECIFIES high octane fuel you will experience pinging(preignition) if you do not use the higher octane it specifies. That will lead to engine problems. If you have an engine like your outboard that SPECIFIES 87 octane you are simply paying more for your fuel with NO added benefit to mileage or performance. Some cars require higher octanes. My sisters Nissan Maxima states right on the car "89 octane" which is midgrade. It's not always available which has been a pain in their @$$ since buying the vehicle. They literally mix regular w/premium any time mid grade is not available. Strait primium is too expensive. They would have never purchased it if they would have known. My brother-in-laws quote: "it ain't a Ferrari"! People all assume our newer outboards are "high performance" or higher compression. They are manufactured and TUNED to burn the fuel they are labeled for: 87 octane or "regular" for our convenience and readily available fuel. :-)