Modern Vespa

I only use Premium grade as it doesn't hold that much anyway so if I'm spending $5 or $7 it doesn't really matter to me at fillup time...just wondering if there is any kind of a performance difference if you use regular unleaded??? Any thoughts???

The rest of the world uses their version of 'regular' and seem to survive just fine. Piaggio do specify 95RON (tranlates to US 91 octane, but 95RON is the 'regular' here) - but things like altitude, added ethanol, all play their part.

I just use the cheapest I can find at a set of pumps, and I suspect across the planet that's what all scooter riders do.

No downsides observed so far.

i have mixed mine in my 150cc with 100 octane and 93 octane 50/50 (making 96/97octane) and i do see a boost in its power. It is not a huge difference but enough that i know it is not all in my head. but i have never used 87 Octane in the scoot to compare it to a low octane fuel.

regular (87) in my scoot and Audi A4. Both run great and pushed hard in bay area driving.

I live in CA, so I use 91 octane gas

i get whatever the best fuel that they have is which is usually 91-94 octane. I live in NJ so we have some of the cheapest gas so why not splurge and spend 5 dollars to fill it up instead of 4.25 ^_^

I use the highest grade at each pump at each fill up. My GTS has never tasted regular gas. That's what the book says...that's what I do. Call me a tool but I love my GTS and it has treated me well so far....

There is no point (indeed there may be reasons why NOT to) in using a higher octane fuel then specified in an engine not designed for it. It'll only hurt your wallet, not much else.

Piaggio said to use 91 octain gas. I think I'll try mid grade next fill.

I use premium, which is usually 91 here. I've heard that it is "cleaner" than regular.

Nope,

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

Local shop recommends 91. Since I'm still under warranty and the manual specifies 91, I'll stick with it for now. The cost differential is pretty small. On my last bike (Vino 125), I checked milage and acceleration and noticed no difference between 87 and 91 octane and finally stepped down to 87. I'll wait till warranty is up before trying 87.
Best
Miguel

The higher octane isn't required for performance, so you won't really detect a drop by using 87. However, the Vespa engine is fairly high compression and requires the higher octane to prevent detonation, which can be a silent killer of your engine. The tank is small, the cost differential isn't going to take bread off the dinner table. Vespa says 91, use 91. Don't try and second guess the people that designed the engine just to save a few nickels.

It isn't a matter of "running fine" on lower octane. It is a matter of long, reliable engine life. Use the good stuff and sleep well.

92 octane unoxygenated (no alcohol) with an occasional dose of Lubro Moly Jectron (Naphtha)

Use what is recommended by Piaggio which is 91 octane by the R+M/2 rating system used in the USA. Europe uses the RON system which causes their octane requirements to appear higher, but it is only due to the different rating system.

The book says use 90 or 91 octane, I believe. Initially when I bought mine this spring, I forgot that and was putting in 87 and mine started backfiring. Once I was reminded that it was supposed to be at least 91 octane I only put in premium (can't find 91 around here--mid grade in this area seems to be considered 90 octane) so 93 is what I burn and my 250 runs well on that. Like other posters have said - the difference in the extra cost is minimal and not even noticed in the pocketbook.

I use premium (91 octane available here) and look for ethanol-free whenever possible (somewhat hard to find here since we grow a lot of corn in KS).

+1

Just an FYI.

Lower octane would actually give you more performance in an off handed way...87 is more volatile than 91.

But it comes at a cost, in that the fuel will ignite from the pressure and heat in the cylinder before the spark plug...well....sparks. So it detonates. It's a horrible thing for an engine to do, which will only result in damage to your motor. Burt valves, pistons, etc.

Usually people will put higher octane fuels in older motors to cure the knocking and pinging that comes about from all the carbon build up and the like. But rarely go the other direction.

So, if it calls for 87 and you put 91, then it hurts nothing but performance.

Going from 91 to 87 is not a wise move. If you do it, listen to your motor on hot days, or when you are putting a good load on it (such as on a hill). If you hear the tell-tale signs of knocking and pinging, back off the throttle.

I use the middle button at the pump. I guess I'll have to look at the next fill up and see what octane it is.

That explains why aircraft air-cooled piston engines need really high octane gas! I am assuming that the engine is capable to taking any octane, but has been tuned to 91, so I put 91 into it.

x2

I guess the "across the planet scooter riders" don't post here, since most all of us use at least 91, or premium!

It isn't a matter of tuning. It is the high compression of the engine that requires premium fuel to prevent detonation. Premium fuel ignites and burns slower, so it is less likely to detonate prematurely.

while I don't have a GTS I do use 93 and really try to use only name brand, like chevron,shell,bp,exxon,mobil, but never ever will I use fu**ing CITGO

Why not CITGO?

Hugo Chavez

http://www.citgo.com/AboutCITGO.jsp

I use 91 in both my 2 stroke SR50 and my 150 Mojito. Made a real difference in the 50cc performance.

Kent

91 Octane in both the 300 and the Buddy..

The company is owned by PDV America, Inc., an indirect, wholly owned subsidiary of Petróleos de Venezuela, S.A., the national oil company of the Bolivarian Republic of Venezuela.

Wayne B

I heard through a couple people that the CA high octane is actually bad for the GTS (like it destroys/deteriorates the engine, or something)

Instead, the mid-grade is the better choice.

Don't ask me. I'm no Piaggio tech. I just follow and respect what my mates tell me.

Why not follow and respect what the manufacturer says? Your mates didn't design the engine, or stand behind it when it was under warranty.

Is that a reason not to use them? I don't understand.

The president of Venezuela, Hugo Chavez, called President Bush "The Devil." That didn't sit too well with many Americans. Hence, some refuse to buy petroleum products from that country.

When it's Rolf Soltau telling me this, I tend to listen (otherwise he'd say "FAWK it!").

I only use the highest octane, around 91 locally. We do have a gas station that sells premium gas without the ethanol, but you have to show up with a can to fill. Still worth it!

I believe that Piaggio has, in fact, stated that CA residents should use the mid-grade gasoline. Whether they've communicated that effectively or not, that's a different question.

OMG! But my Dad's bigger than your Dad.

In Canada, high octane gas (RON+MON/2 =91 or higher) has no alcohol and has the highest amount of detergent. I use it for all of my small engines. Someone mentioned that in Germany you cannot buy low octane fuel any more.

Cheers,
Bob

One case where you want to use lower octane is if you are planning to drive in high altitude. How high is high? I would say over 6000ft.

Less oxygen means less chance of pre-ignition, which is what high octane prevents.