[firefox111]

Hi. The tech at the dealership who did the walkthrough of my brand new 2020 Z650 said that I should fill her up with 91 Octane gas. But when I got home, the manual recommends 87 Octane. What are you filling up your Z650?

 

[sporty]

The higher, the better - always.
But! If your Car\Bike\Whatever needs min. 95 never use less octane if you want to have fun for many years.
Its like electronic devices like DVD and BRDisc, BR devices are able to play DVD, but DVD devices will never support BRDisc. U know what i mean!?

 

[oldenslow]

Use what the manual recommends. 91 won't hurt your engine, but it won't
help it either, and it likely will get lower fuel mileage. Higher octane has no more energy than lower octane gas; it is just formulated to burn later in the ignition cycle to accommodate higher-compression engines. And don't be confused by the fact that US and Euro octane ratings are calculated by different methods. What's 91 in Europe is actually our 87.

 

[firefox111]

Thanks. Actually, I'm in the US and the 91 that the tech said is US 91 Octane. I don't even know if the gas that the dealer put in my brand new bike was really 91! I'll stick with what the manual recommends. Although the manual did not have a warning comment on the use of higher Octane gas. It just said "87 or more".

 

[oldenslow]

As already noted -- higher octane won't hurt your bike. But 87 octane is the fuel it was designed to burn most efficiently, producing the best power and fuel mileage. Buying higher-octane gas is wasting your money, in other words.

 

[Dontnickme]

I alternate 87 & 89.

Anything higher is just wasted $. You're better off doing 87 and adding in stabilizers

 

[firefox111]

I alternate 87 & 89.

Anything higher is just wasted $. You're better off doing 87 and adding in stabilizers

What does stabilizer do on regular commute? I thought they are only used when storing your bike for a long time!

 

[Dontnickme]

What does stabilizer do on regular commute? I thought they are only used when storing your bike for a long time!

I pour in a little seafoam every couple fill ups. Any stabilizers is fine tho when you're using the bike. Check out fort9 YouTube for info. You learn a lot from him

 

[HawkRides92]

I always buy the 92 non ethanol fuel for mine, not because it needs the higher octane but the ethanol in the fuel attracts water condensation. I don't want my tank to rust on the inside.

 

[oldenslow]

I always buy the 92 non ethanol fuel for mine, not because it needs the higher octane but the ethanol in the fuel attracts water condensation. I don't want my tank to rust on the inside.

Not completely unreasonable. But I doubt my '08 Suzuki C50 has ever had a gallon of non-ethanol gas in it, and the interior of its tank is bright and shiny. If it hasn't happened in 13 years, I'm not going to fret over it. I think general maintenance and garaging do more to prevent rust, inside and out, than what gas goes in it. I'm blessed with a nice, tight bike shed -- feel sorry for folks that have no choice but outside parking.

 

[HawkRides92]

Not completely unreasonable. But I doubt my '08 Suzuki C50 has ever had a gallon of non-ethanol gas in it, and the interior of its tank is bright and shiny. If it hasn't happened in 13 years, I'm not going to fret over it. I think general maintenance and garaging do more to prevent rust, inside and out, than what gas goes in it. I'm blessed with a nice, tight bike shed -- feel sorry for folks that have no choice but outside parking.

Yeah, having a controlled climate storage would be nice, sadly my bike is just parked under an awning. I live on the coast so salt air is an issue as well. I also have a 1999 ZX6R and the inside of the tank is quite crusty. But what do you expect on a 22 year old bike.