I use premium only. My manual says 91 or better. Do the new fuel injected motors have knock sensors? If theydo they may retard the timing but it would be at the expense of lost horsepower and mileage.

 

As a fellow Mountaineer I know of what you speak as far as the lack of premium gas at the some rural gas stations. I don't sweat it, I just put in 89 octane and keep on going. In fact, as an experiment, I ran nothing but 89 for several weeks. I noticed no difference in performance or mileage. I then went back to high test. For the little difference in cost between grades it doesn't make sense not to use what the MoCo recommends. What I proved to myself, however, was that my 08 Bob will run with no complaint or pinging on midgrade fuel and so in an emergency I have no qualms about using it without having to worry about rocket fuel / octane booster or dropping in a few drops of good 'ol white lightning.

 

I put in a few gallon"s to the next station. its happened a few times. and to be honest never really noticed much of a difference.

 

Don't know much bout the twinkies, but with my stage 2 with cam evo runs the same with 87, 89, or 92. I can't tell any difference. Maybe a little better mileage with the lower octanes. If on multitank trips, I use 87. If I think the bike may sit a week or so, then I fill up with premium. My owners manual says minimum 87 octane.

 

I add the Octane boost to every tank, just not a whole lot of it, maybe about 2 ounces per 4 gallons, and I only use premium fuel 93 or better.

 

I have run my 07 FZSTC for 5,000 miles on 87 octane. Not a ping or any less performance. I've ran against my own VTX1800 and my son's. It will keep with them until 90 mph. Run 87 in my vette's without a problem either.

I do have an oil cooler on the softail and a Cobra Fi2000r that feeds a richer mixture.

 

OK, I've got a question. Based on my own experience using mid grade gas, as posted above, I'd like to know what the advantage is of adding octane booster. If I have no pinging or other adverse effects when running mid grade gas (and I use it only when I can't get premium) why should I use octane booster. There are some of you that use octane booster even when running premium gas. Again, I ask why.

I'll admit it, I'm an old fart, and have been riding for 48 years. Also, this is the first EFI bike I've had but I've never seen a need to boost octane.

Inquiring, and perhaps forgetful, minds want to know.