Hi I bought my suzuki boulevard s40 new from the dealership. The dealership told me that you can put 87 octane in it but it likes 91 octane. I ran a tank with 87 and then with 89 octane and the bike seemed to respond better with the 89 octane, so the next time I filled up with 91 octane. I havent ridden since the last fill up. I was wondering what octane is best for the bike??? Does anyone have any advice or comminets on this????

thanks

 

I have that same question for my 2008 Boulevard M50.

And BTW, I'm new to this forum and am wondering where all the gear heads are. In other forums I've been on I would post a question and be hit with five answers in the first minute.

 

Hi, what I know is that higher octane the better engine will work...

 

The previous statement isn't even remotely true. The octane rating has nothing to do with rate of burn or cleanliness of fuel as many people believe. Octane rating is simply a fuel's resistance to detonation. Detonation is when a fuel ignites before it is supposed to due to the temperatures that result from compression. A higher compression engine requires a higher octane. Each engine is designed with this in mind so only use the octane rating that your owners manual specifies, if unsure go higher to ensure detonation does not occur.

 

I have heard both sides of the argument. Use the octane specified by manual, and always use highest octane. Most riders I know use 91, so I do. Could I be harming my engine?