Always worth getting the best fuel I recon. Cleaner and the higher octane can give you better performance. Just don't think about the little extra cost... could give you better economy anyway.

be like feeding strawberries to a pig wouldn't it?

Your motors computer is mapped to run 87 and you'll get no real additional benifit from running premium other than a lighter wallet and increasing the fuel companies profit margin.

I have been told my 2 stroke won't enjoy the higher RON of the premium gear.

I am pretty sure that normal unleaded is minimum 91 RON at most servos.

then vortex is 98 - my uncle runs shell 114 lol

lol huggy

chooch , you have just spent close to $ 30 k on a high tech motor and want to save a few hundred dollars on your yearly fuel bill,  i would speak to the motor techs about the fuel and will it cause problems or void your warranty

The service station I used to use, sold out, the new owners, changed the fuel supplier to a cheaper unknown type.

Both my cars started playing up running rough at idle. Apparently this fuel comes in from Singapore and has substute additives in it to make it cheap.

I was recommended to get the injectors cleaned, or else try running on premium for a while. But only buy from the well known brands.

Both cars have cleared up on premium, and now I'm back on standard. Having no problems.

So don't scrimp when it comes to fuel for your boat. 

Was looking up the specs for Yamaha 300 +350 hp engines,the only difference is one uses the high octane fuel, everything else is the same.Bore, stroke, compression ratio so tuning and change of fuel is giving around 16% more power,not bad.

i use premium and always go to a well used servo as high turnover of fresh fuel in the u/ground tanks

Was told by a Yammy tech out of QLD at the launch of the 350 that premium unleaded boosted the hp to 383. We only used premium with that motor and was impressive.

my big donk V8 mercuiser can use lower 91 RON fuel, but I use 95 RON minimum for one reason only.
I'm saving only 8 cents per litre going the cheapo route, but the increased risk of pre-detonation and piston damage with lower RON fuels is quickly out wayed by the savings.
My race bike KTM I tun on hooligan juice, the 100+RON tuff from Shell on the East coast and boosts my performance like a kick in the pants, with the boat, I'd doubt I'd notice the extra performance, but I will see the effects of a cleaner and more controlled combustion on a big block V8 in a few years time when a rebuild is needed.
So my advice is simple.
if you using 200litres of fuel a month for fishing, then you only saving $16~20 max and thats less than slab of beer, is it worth it.... ???? Go the best fuel you can afford route.

http://www.themotorreport.com.au/6915/the-real-mccoey-on-ron-research-octane-number

http://phorums.com.au/archive/index.php/t-225281.html

http://en.wikipedia.org/wiki/Octane_rating

couple of reads for you

and one from Rolls Royce, not boating but a good explanation of why fuel RONs have changed and the effects on their cars
http://rroc.org.au/wiki/index.php?title=Technical:Unleaded_Fuel
ps when the blend fuel at the refineries, the low RON fuel gets most of the crappy hydrocarbon short chain stuff in with it and the higher RON fuels are better balanced with long chain hydrocarbons, bit technical but google it...

was told the Verardo 350 can only run 98, not 95 (warranty reasons) however the lower hp verardo's can run 95

performance,

 its useless to run premium in a engine that was not DESIGNED for premium fuel.

all the premium does is reduce pinging known as detonation when the fuel air mixture in your car rpeignites, the higher octane level is more resistant to preignition

 premium just burns slower so the mixture doesnt preignite

all high preformance motorcycles run of premium because theyll ping without it

 but anything thats designed to run on standard will be worthless to run premium

so if youre manual says to use premium use it

the same, bought a new top loader washing machine, highly recommended to use side loader washing power, as this washing power doesn't create suds and will not clog your pump when pumping water out , so I will follow the recommendations and use front loader w/power. 

Recommendations are there for a reason, so it would be commen sense to do what the manaufactere says.

remember most of these user manuals are for the US market 87 fuel in the US is our 91RON fuel here, all modern engines will have the ability to retard the timing if the fuel isn't right at the loss of some power and economy, running higher octane fuel will be of little benefit especially when it's not tuned for it. Unless people are now using EMS software on their outboards and tuning the motor to suit the fuel you are wasting your time.

if it sayd 91RON fuel, use it, or 95/98RON for upper end motors if recommended then use that and nothing else.

To get the most advantage out of running high octane fuel is you must have the comp to burn it , ive got a blown 57 chev and ive tried a few different fuels .

Tried 110 octane avgas and the car ran slower due to not being able to burn the fuel as to lower octane fuel it might run a bit cleaner but i dont think the saving on cents per litre is worth it.

remember what I said,about fuel quality and what additives and cr@p they put in.
I worked for many years in a oil refinery producing fuels and chemicals. You toss all the rubbish in the fuel streams and keep the good clean stuff for the pure chemicals market where you get 300% more for it.
Premium fuels will always be better balance, refined and cleaner than the cheap stock bottom of the ladder RON stuff.
You may not get all the ooomph out of premium fuel with your car if it's not capable of the higher combustion efficiencies etc... but you will get the advantages of a cleaner burn and less long term issues.

I use the cheapest fuel I can get on the old banger I ride to the station ( 1984 Toyota)
I use premium unlead on the Jeep and Mercruiser.
on my race motor KTM, I only use drummed fuel from Shell on the east coast, cause a motor rebuild on that little kitten will set me back close to $8000!!!!

Even though the Jeep can run on lower RON, we have seen the difference in fuel economy between 91 and 95+ offsets close to the cost difference.
nearly 1.2 litres per 100 difference on the open road. or close to 10% saving using the higher RON fuel. Mostly due to the timing being automatically adjusted and advanced by the on-board engine management computer etc ..