With gas now $4.05 a gallon...

[rem]

The price of gas and resulting cost of running my bikes may very soon become one of those things I just don't want to know too much about. It's something I'm going to do, and worrying about the cost would detract from the experience, so I'll just suck it up (as will the bikes) and enjoy the ride. I'll just have to cut out other thing like food, shelter, warmth ... and other non-essentials. I'm not ready to throw out my padded shorts just yet.


Hey, it's supposed to be 60 degrees here today. Heh heh. And 70 on Tuesday. HEH HEH. Old dog gone. R

 

[Checkswrecks]

Using Regular instead of Premium is OK and does not hurt the engine because the Knock sensor protects the bike.
What is interesting is that often Premium is "cheaper" to run. The difference in price is around 20 cents per gallon. At ~$4 per gallon that is 5% more expensive. BUT, the way a knock sensor works is that it retards the timing for the spark to prevent knock/ping. The effects of retarding the spark are three-fold:
1. the engine runs less efficient and at lower power per volume of gasoline;
2. the engine runs much hotter;
3. the oil gets a little dirtier from blow-by past the rings.

Running on Premium you should get 10~20% better gas mileage (if you use the same amount of power and don't go crazy with acceleration). I have seen this on multiple bikes with knock sensors!

That means that Premium should be at least a 5% savings! YMMV

The S10 doesn't have a knock sensor though.


We're going to have to see how it runs on regular when the US-specific version arrives. Guessing from other models earlier, the reason for us to need premium is that Yam had to advance the timing and/or lean it to meet our EPA or California requirements.


Until hot day and heavy load, it'll probably run just fine with regular.


As to the original post, I took a bunch of values from earlier threads and typically got mileage of 44-47 mpg, with some into the 50s and some into the 30s. I get 48-50 on my FJR regularly and am expecting 1.5-2 less. The wild card is how they've changed the timing and mixture for the US-spec bikes, though. As with whether we all will always need premium gas, we won't know the exact mpg range for US-spec bikes till they are here.

 

[MotorcopBBQ]

I go by the owner’s manual when it comes to what gas to put into the motor. When I bought my Buell the original owner put nothing but 87 in and it suffered. But it was a carbureted bike. I've never put anything in 87 in my current bike, in fear just look back on how much money and time it cost me from a person just trying to save a couple of cents.
All this talk about st1300's is going to make me want to look at them.

 

[Yamaguy55]

I don't think you will have a problem at all - especially since the ST1300 has a knock sensor. I use to own a Honda S2000 and a Mazda MX-5 and they too "recommend" premium. In both cars, I ran regular often and never noted a difference in either performance or mileage.

It may be a problem at lower elevations or colder/denser air. You guys still have 83 or 85 octane as regular out there? It was something like that when I was there in the mid eighties.

 

[mobyfubar]

As they say, YMMV, but mine didn't.

Same for me, Fred.

 

[colorider]

It may be a problem at lower elevations or colder/denser air. You guys still have 83 or 85 octane as regular out there? It was something like that when I was there in the mid eighties.

85 is our "regular" here (also in some of our surrounding states).