what octane level should I put in my GRiSO?

I have a typical "newbie"-question - sorry about that.

When I purchased my new (secondhand) 2007 GRiSO last week, my very knowledgeable sales guy at the MG dealership told me to only use octane level 92 or higher.  "Sure", I thought. "No problem".  After arriving back home though, I found out that the gas stations (Shell, Husky & Petrocan) in my little town only sell max 91. There is some variation in ethanol level, making Shell's "V-Power" petrol probably the best choice, but still - it is not 92.

Does any of you know how bad it is to use the 91 V-Power for my new baby?

Thanks!

Just use the highest you can get and if possible get ethanol free.

Pete

I have run on 87 regular several times (no choice) with no discernible detriment. Given the choice, I always buy premium. In reality, I don't worry about it.

I "feel" premium is a bit stronger but I am biased.
My wife's Gladius manual recommends AVOIDING anything over 87 octane due to not getting any benefit from higher octane. Her bike was specifically designed or tuned for 87.
What ever.

DM

when they say highest you can get do not use av gas or race fuel, and when they say use real gas if possible I concour 100% BUT BUT BUT do not do not do not use Rec Gas (sold as 100% at marina areas etc.) with MTBE in it and then go back to eth blends. you will get glue in your tank pump lines and injectors.

so best 91-93 r+m/2 100% no combustion modifiers
next 91-93 eth blends

from logging data the motor seems to run better (heat wise) on 91 eth than 87 100% (mine will ping just a bit with 87 100% in high load)

I run regular. I think I've put in one tank of premium, no difference. The dealer in Tucson recommended regular when I bought her so.... I have not had any issues using regular. The only pinging I have experienced have happened when I accelerated from a dead stop and was in 2nd gear instead of 1st. Oops.

Thanks everybody!! Very helpful. Good to know that it is not a matter of (the bike's) life or death after all. And using Shell V-Power is just fine!

Even using premium gas (91 octane) I am experiencing noticeable pinging under hard acceleration crossing 4500 rpm - it is quite an annoyance. The crappy ethanol laden gas here sucks.. Yes, my hearing is perfect, yes I know what pinging sounds like (no it isn't another mechanical rattle). Wished there was a way to get rid of it. That is one of the few gripes I have with an otherwise perfect motorcycle. The GRiSO is a 2013 model with no mods to air/fueling/ecu - curious to see what could be done to reduce or eliminate the pinging..

Throttle body imbalance can cause pinging.

Is it coming from the right cylinder?

Now that you mention the right side, yes the noise appears to be coming more from the right side.

Hmm. The delta-fuel correction table in the stock 03 map is woefully lean. It is exacerbated by the lambda correction. Therefore, the right cylinder runs lean in closed loop and that crap you guys have for fuel does not help.

If there are no issues with the throttle bodies or spark, then there are two things you can do.

1. Get the lambda switched off and run the stock map in open loop.
2. Reflash a new map. If you want to stay with factory closed loop, replace the 03 with the 68S. It is far superior.

I keep telling Chriso to use ear plugs so that pinging goes away. But these young guys think they know everything.

We'll work out a time soon to pull off his current map and insert your latest map and see what it does for him. Beetle, if you have the 68S map could you email it to me?

One final note on gas, I do make an effort to get just Chevron or Shell gas. It has made a difference with my cars so I try to use the same stuff in the bikes.

And balance them turtle bodies...

I never made the claim "I know everything" - I just "hear everything"....  

He hears voices...

I just make friends with the voices in my head.

But as far as engine noise is concerned, I have to take my helmet off to insert the trumpet, then I get ram air & bugs, so I don't bova.

Pulling a tiny bit of advance helps here and there, the real problem with the eth fuel here is the blend changes all the time. IT can be UP TO 10%... from indy stations it rarely is why, Ethanol is more expensive than gas (very often), so you actually can save money by mixing in less than 10% as a generic fuel supplier.

You can get more consistent running with branded fuel here a lot of times, as the mix of eth is consistent. The 2nd line suppliers blend based on price of components, when oil is cheap and corn is high you get 100% gas frequently even though the pump says 10%eth

a lot of states really fuck up the blends badly by regulation, No engine ever ran well on the winter blend 83 octane shite they sold when I lived in denver, 87 with 10% eth, and "oxygenation" additives were sold as premium...I know the octane can be lower in the higher altitudes  , but the extra additives and the eth really made for shitty running. 

I just found a gas station that has 100 octane race fuel.
I'm glad I read the recent posts here because I may have saved myself some trouble.
I will have to check the other "additives".

dm

Yeah it's Summer in Phoenix and so our gas goes to shit... Ethanol and then even worse they oxygenate it. So it has even less energy per oz.

rboe - I run 91 in mine all the time, never tried less.. might have to give that a go just to see, but remember 91 will have better cleaning detergents versus little to none in regular grade. you should run a fuel system cleaner every once in a while . I recommend Red Line Fuel System Cleaner.. amazing stuff

Steak wrote:

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thanks yeah the 95 VP gas right by my house is like $6.50 a gallon at the pump.. ouch versus the 4.09 a gallon for 91.
I really should try it for a group ride!

If you believe the ads, regular has the cleaning agents too. I should not be missing out on those. I have used Redline based on your recommondation, especially with bikes that are idle (e.g. the XR650L) for long stretches. So far, it seems as good as Seafoam but nothing really scientific.

Higher octane does not contain more energy, just a higher resistance to knocking. But being older and more deaf perhaps I'm missing something.

ok I am gonna step in the shit here but i don't care...I love SEAFOAM it has made me more money cleaning carbs than anything else ever...every damn red neck with a bass boat has a can and will pour it in his bike that sat over the winter. and bingo I get a job cleaning the goop it fills his carbs or fuel injectors with. Great stuff bring it on.  

Stay away from startron though the stuff aprilia factory advises to blend in...since it showed up in the atv shops I don't make any money cleaning the fuel systems on the hunters atvs any more    

Very interesting. I was under the impression it went into the gas BEFORE you had problems. E.g. when you put the machine up for the winter.

rboe wrote:

If you believe the ads, regular has the cleaning agents too. I should not be missing out on those. I have used Redline based on your recommondation, especially with bikes that are idle (e.g. the XR650L) for long stretches. So far, it seems as good as Seafoam but nothing really scientific.

Higher octane does not contain more energy, just a higher resistance to knocking. But being older and more deaf perhaps I'm missing something.

Depending on the brand Regular has cleaning agents but I do know that Shell and Chevron premium have more detergents from someone in the industry. I can't speak for others... except cheap gas skip the expensive cleaning agents. Premium Shell does have fuel stabilizers in it to help with longer term storage (not 6 months)

the difference in the 95 octane VP race gas is no alcohol and no oxygenation here in Phx so it does contain more energy. Basically if I could buy 91 without Ethanol and oxygenation it would perform better and consume less gas. if you can't pass emissions you can run race gas which burns cleaner or add more alcohol.