Modern Vespa

Tried to do a search on this but while a lot of stuff came up there was nothing on Octane levels.
The users manual for my 2007 LX 150 states that a minimum of 90 octane fuel should be used.
My question for those of you that have a lot more experience with scooters is will 89 or even 87 octane really hurt the engine?
I met a guy with a 250 City Sport who told me he uses 87 and has had no problem - its hard for me top believe that the 250 would require less octane than a 150 especiall since they are both made by the same company.
Help!!

This has been hashed over and over and over. Some of us say only burn the recommended octane of 90, or 91 if that is all you find. Others say that European fuel grades are different than domestic and their high octane is our 87. Then there are those who say they burn cat piss and have had no problems. The tank of your scooter will probably not require more than a couple of gallons at best to fill up. It might cost you 25 to 40 cents more to top the tank. I have the same scooter and burn premium fuel because the book says to. I am willing to spend a little more to remove all doubt.

Now, If you really want to get the ball rolling, ask about oil and oil change intervals. Don't say you weren't warned.

I would agree with NightWing,

However I notice you're from NC, so if you're having problems finding premium (as we are sometimes around here( You can run 87).

But I finding that mine likes premium better.


And NightWing you left out belt and roller changes.

I think this point is less what others say and is more fact... U.S. and EU octane values are not equal. That said, I generally agree with everything else you said.

To the OP, keep in mind that the SportCity belonging to the guy you met is fuel-injected - your LX is carbureted. I don't know if that makes a difference in our scooters, but many cars have knock sensors that will retard the ignition timing if you use lower octane fuel. I'd be more apt to try lower octane in an EFI scooter than a carbed one, anyway.

I think some of the confusion/reason to argue about the difference in ratings overseas versus US is that the Vespa literature just says 90 or 91 octane.

I would like to believe that the people who translated or wrote the advertising pamphlets and books had the common sense to convert the octane rating to one we are familiar with.

The LX brochure I have in front of me gives two descriptions for just about everything. Weight is lbs/kg. Bore and stroke is inches/mm as well as length and width. Speed is mph/km/h. Everything is described in units accepted on both sides of the pond...except fuel, which is 91 minimum octane.

If they had given a dual octane rating, it would have taken all the mystery out. So, based on what I read in the brochure, I feed my Vespa premium fuel.

Just checked my manual to make sure, and where octane is specified it does state (M+R)/2 Method 90. This is the North American standard.

I think I'm not going to comment on octane threads anymore.



cheers

Woodenhead, YOU have ,made my day! I just went out to look in my book again. I knew it said 90 octane, but I never picked up on the method. Not only is it in the manual, it is right on the warning decal on the headset, right below the speedometer. This calls for another thread!

I just went and checked in another Italian owners manual for the requirement and found this. Ok, so it's not a Vespa but I don't remember seeing 97 octane ever. We had been feeding it 93 but that is getting harder to find so 91 is the new diet. No running problems and still able to get one into trouble in a hurry.

Oh boy, THIS thread again!

IMO, using a lesser octane wont damage your engine if you do it only once in a while. Repeatedly, thats different story. It may be best to just follow the specs for the engine that Piaggio provides... If you are having a hard time finding premium, you can add a little octane booster. If you are just looking to save a bit on gas, just dont. You spent the money for your Vespa, protect your investment and give it the best fuel you can get. Thats my .02

Thanks to all for the helpful advice. Yes, I do live in Western NC and we have been having quite a time finding any gas - and yes 87 octane seems to be more available than premium. Will try to find a station today that has at least 89 octane but will continue to use 90 on a routine basis.

Re: Oil and oil change interval, I live about 35 miles from the nearest Vespa dealer and have been having a hard time finding the "Correct" oil to use. Sooo I bought Castrol fully synthetic 5w/40 with the correcxt API std. and it seems to work fine.
According to my manual I am due for another change at 4k miles and I think every 2k after.

Cheers!!

The fact that you even bothered to check the API std. on the oil you bought suggests to me you'll be just fine.

Yeah, don'tcha love these threads?

My 2c is that it really doesn't matter unless your scoot exhibits pinging from premature detonation...and with respect to what exactly that is, my rule of thumb for the uninitiated is that it's like porn...you know it when you see (or in this case...hear) it--especially on a one-cylinder scoot.

The risks of premature detonation are not only dependent on octane of the fuel being burned, but atmospheric conditions too...temperature, humidity, altitude (oxygen richness), as well as the particular tuning of your engine. The impacts of octane choice gets rolled in with all of the other characteristics noted above to determine how your engine performs. If it's off, you have a huuuuuge range of under-performance that poses no threat of damage to the motorcycle at all. Some would argue that over time, the collective under-performance of octane lower than what the bike had been designed to burn will contribute to the shortening of the engine's service life. My take on that is that such an argument is well applied to things like oil choice and frequency of oil changes...but doesn't make alot of sense when it comes to engine component stresses. The fact is, so long as the engine is reciprocating as designed...engine stresses don't deviate that much from design specs.

Premature detonation is the only situation associated with octane choice that truly accelerates wear on an order of magnitude outside of the norm. Until you get to the situation of premature detonation, the variation in engine stresses felt by lower octane is really insignificant...particularly if you have an ECM involved, managing combustion timing, advancing and retarding the ignition timing as needed to optimize combustion. But cross into the scenario of premature detonation, and it's an entirely different picture. It takes what was a smooth reciprocating motion and introduces relatively huge amounts of shock and impact on the bearings and bearing surfaces in ways that engineers never intended it to take. That's the difference. Premature detonation is the game changer that takes your materials into an accelerated level of wear. And that's the only thing that anyone really has to worry about. Will you *actually* damage your scoot if you don't follow the guidelines? That depends entirely and only on whether you are experiencing pinging. If you're not experiencing pinging...you have nothing to worry about. And it doesn't help materially if you chose 90+ or 87. If it doesn't ping with 87, you're fine. And there are many many scenarios where 87 really works fine. For instance...you have to have a pretty severe mix of ambient conditions to get pinging with 87 octane around where I live. It has to get damn hot out.

The thing is, though, when you *do* get to the situation where you're listening to your engine and thinking "wow...that does *not* sound good!" What are you going to do? What if you still have just about a full tank of 87octane that disagrees with the weather? That's the compelling reason to stick with higher octanes, bcs you really really don't want to be in the situation where you're hearing pinging. Think of pinging as your engine's own little internal hammer hitting itself hard over and over again like a dumb kid. Your margin of error is quite large up until you hear pinging. But after that...the penalty for error is regrettable. Dip into that scenario a few too many times, or flog your engine through it long enough and you will definitely start down the path to ugly engine wear, and the worst case of a seized engine. Will it be worth it?