I use Premium because I don't always ride as frequently as I like. Unlike several of the other members on here I don't rack up the 1,000s of miles every year. I started riding mine late last July and I've only put on about 1,000 miles so far so the difference in fuel cost is not significant.

I just use the cheap stuff in my thumper but she is liquid cooled, I might use better in an air cooled motor.
Clive W

100% gasoline 87 octane

My mistake... it is regular that is recommended as minimum.

verslagen1 wrote on 05/23/10 at 10:17:02:

Here in Nebraska they push E-10 (formerly called "gasohol). Sometimes they describe it as "enriched with ethanol." Some on the Forum consider it as "contaminated with ethanol." The E-10 is usually several cents per gallon cheaper. It is usually 89 octane (mid-grade) while the regular is 87 octane. Some stations offer both fuels, while others offer only E-10. Premium is harder to come by, as my brother discovered when he visited (His Mean Streak calls for 91 octane minimum).

I have been using E-10 in cars, motorcycles, and mowers since the late '70s. It has caused no harm to any of my equipment. I have tried to measure differences in fuel mileage, and have been unable to do so. The only effect I ever noted was better knock resistance using E-10 in a '79 Lincoln, probably due to the higher octane.

Because of the reported potential for phase separation in the presence of water, I avoid E-10 in my boat and other two-stroke equipment. Most manufacturers seem to say ethanol should be avoided when equipment is to be stored for a while, such as over-winter. So, come about September I start putting what Bill calls "100% pure gasoline" in the bikes and mowers. That way when I store them in late October most of the ethanol should be out.

I use reg as when I did ride I usually rode a tank every few days sometimes twice a week.

I use regular... when I first got the bike, I used premium.  But then I asked the gas station attendant how much premium they sell, and he said "hardly none!".  I don't know how often they change out the tanks, if the fuel doesn't get used, and after reading discussion here about gas getting stale, I switched to regular.   I haven't seen any negative difference.  I actually get better gas mileage now, but I think that can be attributed to more things than gas, so I don't actually know the effect of the gas change.  But to me, fresh regular is better than stale premium!