Fuel grade Excalibur 330 hp

[Flyerace]

What fuel grade are you guys using in your Excalibur 330 hp? The manual says 87 octane, but a sticker afixed to the engine says 89 octane. Thanks in advance. :D

[skinautique]

You can run 87 but make sure it has NO alcohol in the gas or else you will shorten the life of your fuel pumps!! Jeff, the sticker is on the back of the red cover over top of the engine. It has that along with spark plug info and more on it.

[NautiqueJeff]

Hmmm... That's odd that PCM would put a sticker like that on the engine, and then have their manuals state something different. It would make more sense to me if it was a sticker put in place by GM, but if it is on the cover, that's something PCM did. Weird...

[Flyerace]

That's correct, it's on the plastic cover on the top of the engine. As you stated, it also includes other specs for oil, spark plug, plug gap, etc..

[Flyerace]

Are you saying that 89 and higher does not have alcohol added to it? Why would you specifically be wary of 87 octane containing alcohol? Thanks

[skinautique]

I would be wary of any gas with alcohol in it. It doesn't matter what octane it is. It just can't have any alcohol in it because it eats things up such as the fuel pumps and they are not cheap to replace. Look on the pump when you go the station and it will tell you if it contains alcohol/ethanol in the fuel.

Hope that clarifies it.

[SGY]

I'm also perplexed. I always understood from the manual that 87 was required. I even recall reading somewhere that the motor won't run as well on higher octane due to the slower burn rate. The timing and other settings are set up for the specific burn rate of 87 octane.

Also, I just run pump gas. Never looked to see if it contains alky. I know that alky is corrosive on plastic and rubber parts. I guess I better be more cognizant.

[ag4ever]

I always run 93 in mine, but then it is a 2002, and does not have a red cover. My cover is silver, and has no stickers on the back of it.

I run 93 as I don't put that much fuel through the boat, and want some of the extra additives that the fuel mfgs put in the higher grades. I have also heard the higher grades are more stable, and don't varnish as fast as the low grades.

[MarkP]

If your motor does not have a ping to it and your running 87 octane more than likely your motor is set for 87. Running advance timming will cause the need for higher octane and that's why it pings while accelerating!! The
burn rate is faster on low octane and slower on higher!!

[Rick]

I have a 2000 GT-40 EFI and the sticker says 89 octane. However I spoke to the mechanic and he told me that 87 is just fine as long as its fresh. If the boat sits and isn't used weekly make sure you add STA-BIL or another stabilizer. Here in California I think all the gas has alcohol in it so there isn't much we can do about it.

[Hollywood]

There is also only 1 Amoco I know of around me that doesn't have alcohol in their gasoline. You're not going to benefit running 93 when you don't need to.

[tryan]

go with the 89 octane. i would rate the sticker on the motor higher than the manual. who types out these manuals anyway? (no flames, but you will see a DECREASE in performance with a low compression motor running premium fuel. higher octane burns slower. less chance on detonation, but a decrease in performance because of the slower burn.)

fuel will loose aprox. one octane point per month, so try to use as much fuel as you can before you refill the tank.

[SGY]

Yep, page 25 of my PCM manual specifically says: "Most PCM Fuel Injected engines are calibrated to operate on 87 octane fuel and maximum performance is obtained when using this fuel. The use of higher octane fuel in these engines, besides added operated costs, can cause temporary performance loss. Therefore, the use of these fuels is not recommended."

I'm going to look for the sticker on my engine. If it says 89, then I'm going to call PCM. To find out what to do. They don't even sell 89 octane fuel in most places in Colorado. It jumps from 87 to 91 octane. Kinda like not selling a medium drink at Wendy's. (Ok, bad analogy.) I suspect at my altitude, running a little lower octane fuel is not a huge problem. Not enough air up hear on normally aspirated motors to get alot of compression anyway.

[NautiqueJeff]

I just sent an e-mail to PCM on this. I'll post their response when I get it.

[lcap]

Does the summer blend fuels we have to use on the West Coast have any affect on what Octane or Additive we should use? I went through 2 fuel pumps on my Sport in 9 years.

[BigBald]

Does this octane usage of 87 versus 89 change from year to year? What about '99 - 330 hp engine?

Also, is there any long term impact to using a "higher than required" octane? The reason I ask is that during the summer we spend a couple of weeks on a houseboat. We are basically forced to use the marina's gas. I seem to recall that this is "super unleaded" which may be like 91 or 92 octane. I haven't notice any reduced performance issues.....but should I worry about some long term effects?

[scooby]

I actually had the same question on my Python and email them and received this as a response. I hope it help.


"All the engines we produce are built to run on standard 87 grade fuels. The decals have been changed to reflect this. "

[Nautiqueman]

As for the alcohol in the fuel- I have always heard to make sure my fuel is free of alcochol.. Not sure for the exact reason, but thought it was not good for the total fuel system in boats.

[skinautique]

Nautiqueman,
The alcohol will eat up your fuel pump and you will have to replace it much sooner than you would like to.

[Rick]

Basically Alcohol attracks water molecules to it (Hydrophillic). As a result when you have alcohol in the fuel there is also a certain amount of water associated with it . This then pitts Carbs and exhaust etc.

[Flyerace]

I spoke with PCM and they said use 87 octane. They will change the stickers.

[UWSkier]

Using anything above 87 octane is a waste of money on these fuel-injected engines. The biggest horror stories of running gas with alcohol in it is from 2 stroke outboards with older carb configurations. The alcohol introduces extra oxygen molecules into the mixture and can lead to cylinder scoring and compression loss. This isn't an issue with our fuel-injected 4 strokes though. If you can get gas without alcohol, do it, but if you have no choice, don't worry too much about it.