KBondra

Hi, Should I run regular or premium gas in my 32 Sunsation? It has stock 385hp 454 mags.
Kevin

TexomaPowerboater

Premium. Boats often sit for long periods of time without use. If you run 87 you will increase the risk of detonation. Its cheap insurance. Also, if your running a boat that has sat for longer than a month you should stay off the throttles until you get some fresh gas in there.

KBondra

I thought the fuel injected engines were made to run regular.

JMS322

There is NO advantage to running premium 93 octane fuel in an engine that calls for 87 octane. In fact it is proven that it may even produce less hp than the 87 octane, therefore may be a tad slower. It does on the other hand smell a lot better.

Dave M

87 octane.

ActiveFun

Whatever your motor was designed to run on. Its a pure waste of money to use premium if your motor was designed for 87 or 89

techman

Whatever your engine manual says to run!

Probably 87 for those motors and if so, there is NO benefit to running the slow burn higher octane fuels and in fact may lose some performance as others say. Whatever you run, make sure you buy it from a reputable place (fresh and clean). And use it up. If you must store it...stabilize it.

Knot 4 Me

87 octane with 454 MAG MPI's.

Interceptor

[QUOTE=techman;3465318]Whatever your engine manual says to run!

Best advice.

Crossett

You want to run the lowest octane you can get away with without detonation. Lower octane burns hotter and more complete and will make more power. In the case of a 385 horse 454 mag it's almost certainly 87 octane. ( I say almost because I have no experience with the mag, although my 330 horse 454 runs like a top on 87). A good indication is the compression ratio, if it's under 9:1 then 87 will be fine.