The Mercury website says that it's built to run on 87 octane but I was always told to run supreme on a blower motor. I'd like to hear from other people that have a Merc 600. What gas do you run?

http://www.mercuryracing.com/sterndr...gines/600-sci/

I only run 91 non eth octane gas . Not worth the worry .

I know you can run 89 in the 700. So I bet it would be ok for the 600 Greg. But then again- better safe than sorry. Merc normally knows what's up tho.

Did you get it out yesterday?

Stock tune motors are more than safe with 87. I would try to stick with non-ethanol fuel, seems better all around operation especially in the heat of summer.

Where/how do you get non ethanol fuel when the fuel supply is what is at the local gas stations?????

This might help you find a station. I found a station that sells marine 89 at $1.10 less a gallon than on the water right by my house.

http://pure-gas.org/

Just curious why you would want to save a few pennies per gallon and take a risk of potentially hurting the motor from detonation. I could see if you are in a bind and 87 was the only thing available but it is just cheap insurance to run premium fuel.

I remember this exactly because last year I had to show a owner with a 600 SCI per OEM service manual racing # 14 - Merc Racing lists the 600 sci and the 700 sci oem stock and of course stock tune - US gas blends - Unleaded 91 octane or RON = 98

Added info = Also FYI had to prove that MERC lists again SM # 14 Supercharger oil lists Castrol Syntec 5 W- 50 - for the same owner.

Any NA sayers I will send you copies per MERC RACING OEM Service Manual to frame on your wall.. I can careless what the marketing team shows in their listings for the current offerings as this was not a current brand new engine either. Things change and ECM tunes change as well thru out the years. Just saying

Not looking to save money at all, I just want to know what the best gas to run in it is. The reason I ask is because with the 496HO's and 525's they actually run a little better on 87 and don't soot up the transom as much.

Around here they have started selling Rec 90 no ethanol. I have thought about running it in my 700sci's. Probably wont do it but it is tempting.