premium gas

[twistable_deer]

hello, i have a 2006 1800mx and i use it for wake boarding and tubing and i just put regular 87 gas in it and people keep on telling me i should put 91 or premium. are they right?

Thanks

[rens914]

the question is why ?
i have owned a lot of supercars (lotus esprit turbo, TVR Tuscan, porkers, tomaso pantera) and couldnt really say that there was much to gain.
yes these cars (heavily tuned engines) respond better to the trottle but it was only usefull on the track.
when are you going to use the full range of power in youre boat
sure you'll need it to take off but after that you won't open the trottle further than 3/4
it's yust a waist of money
YM2C
rens

[twistable_deer]

but my cousin said that it prevents knocking which can crack the block or piston. what do you think?

[rens914]

no idea
have the 4,3 l v6 vortec and use 95 RON
engine runs great
rens

[brianbossman1]

Unless your running 11 to 1 pistons (which your not) 4 or 5 octane points higher is not going to make any difference. I have never had a problems and I just ran through 70 gallons today with no problems.

[vffb507]

I asked this when I bought mine (of the first owner).... He said he only ran regular 87 octane... Keep it maintained, don't beat on it and it will run fine... Mine's a 97, 1700 with a 3.0l and runs great, no knocks, starts quick and responds good all with 87 octane. I do however use a additive for the effects of our wonderful ethanol fuel..

[TBarCYa]

According to the specifications on their website, Mercruiser says 87 octane fuel.

[twistable_deer]

thanks for replying

[biggerseagar]

TD...........sorry I have to put my 2 cents in here.............this is why you read your owners manual........what does mercury tell you? 87 right...........

Cousins like that.......IMHO need to watch what they say.

Adding more octone to your engine does nothing but drain your bank account faster.

You can add an octane booster if you want too, but again that will be throwing your hard earned money away also.

Listen to your engine ......it will tell you what it wants.

Roger

[ss3964spd]

Originally Posted by TBarCYa

According to the specifications on their website, Mercruiser says 87 octane fuel.

And that's the key bit of information.

Higher octane fuels actually burn slower than lower octane fuels, and are specifically for use in engines that would experience pre-ignition (the fuel mixture - air and gas, ignites BEFORE the spark plug fires). Pre-ignition is AKA pinging, detonation, etc. The engines compression ratio, cylinder head combustion chamber design, ignition timing, camshaft lobe design, and at what temp the engine runs all factor into what octane gas the engine needs.

Higher octane gas is more resistant to pre-ignition and burns slower than lower octane gas. If your engine is not suffering from pre-ignition when using 87 then there is zero to gain by using a higher octane gas. Indeed, you could even see a slight decrease in performance (though you'd be hard pressed to notice).

Dan