PCM ZR409 engine recommended fuel

[Soul_surfer]

Since this morning I'm searching what recommended octane the zr4 is running with but ain't finding anything.
nautique website, pcm motors too. Anything about fuel.

maybe some here can tell me wich one are you using?
i know for optimal result always should drive with 95 but what's recommended.

i've seen on few thread that some people runs this engine on 87 and put stabilizer in it.
Never done that before and maybe not a fan but what's your opinion?

my last boat was indmar raptor 400. Recommended 89.
And it's 89 octane that I will put in my new 2017 PCM 409 too. Simply curious to know what's really recommended on the motors paper.
thanks.

[scottb7]

I run 87 and it is fine. http://www.pcmengines.com/owners/

[charlesml3]

Yep. 87 Octane is perfectly fine. Anyone that tells you it'll run better, pull stronger, or last longer on 89 or 93 Octane fuel doesn't really understand what Octane is.

-Charles

[Evening Shade]

Yep. 87 Octane is perfectly fine. Anyone that tells you it'll run better, pull stronger, or last longer on 89 or 93 Octane fuel doesn't really understand what Octane is.

-Charles

So true!

[imhoff]

What do you think the rational is for recommending 93 in the 450 and above engines?

[charlesml3]

What do you think the rational is for recommending 93 in the 450 and above engines?

A lot of people equate higher Octane with "better." It isn't totally their fault. The fuel manufacturers perpetuate a myth that 87 = Good, 89 = Better, and 93 = Best. That just isn't true. The higher numbers mean those fuels contain a higher percentage of the compound Octane. Octane is an anti-knock (technically predetonation) compound. As manufacturers have sought to get more HP out of less engine, they've increased the compression ratio. As a result of that (and given the limitations of internal combustion engines and the fuels we have) these engines tend to develop knock. This isn't good for an engine. The manufacturers have added all kinds of sensors to detect knock and take measures to keep it from damaging the engine.

There are some engines that absolutely require higher Octane issues. Pretty much any engine with forced induction does (like the 550). Those compression ratios really don't like lower Octane fuels at all.

-Charles

[Soul_surfer]

Thanks for the advices.
Yes i totally understand what octane is
higher octane meens higher detonation and most people think higher octane is better but not every engine needs higher detonation that's the thing. Only the ones calibrated for that.
but I don't really know boat engine instead. That's why I was wondering.

so you tell me now in my brand new Nautique I don't even need to put 89 lol..
with no stabilizer either!

Just good things with these boats haha

[GemCitySurf]

Thanks for the advices.
Yes i totally understand what octane is
higher octane meens higher detonation and most people think higher octane is better but not every engine needs higher detonation that's the thing. Only the ones calibrated for that.
but I don't really know boat engine instead. That's why I was wondering.

so you tell me now in my brand new Nautique I don't even need to put 89 lol..
with no stabilizer either!

Just good things with these boats haha

Ehh...technically, the PCM manual DOES recommend a stabilizer for ethanol blend fuels. You will have plenty of people argue that it isn't needed or they have been not using it for years and they are just fine, but at the end of the day...PCM still recommends it. I use STA-BIL 360 Marine during every fill-up.


Sent from my iPhone using PLT Nautique

[Soul_surfer]

True.
just read it in the PCM manual.
And that's what I'm gonna do. Don't want to mess with a new engine and I'm already used to pay 89 octane fuel so paying 87 now I can easily buy a stabilizer if that can help.
here in Canada pretty all fuel brand "may contain up to 10%" ethanol either 87, 89 even 91 in some brand.
only Shell certified 5% ethanol in 89 and 0% 91 and up.

thanks

[sfjakey]

I know for a fact with my ZR6 in my 211, if I didn't run 91 octane, I would foul plugs quite frequently. Switched to 91 and the problem stopped. I have only run 91 in my 230 with the ZR409 so I cant comment on 87, but I also havent fouled any plugs either.