No, not for sure. I have a '07 and it has the sensor, but I'm not sure what year it was added.

 

07 road hawg when i bought the bike i ran 91 octane in it and i had spark knock like you would not believe, took it back to the dealer told me it was normal. i'm not a rocket engineneer (or spelling for that matter) but i know he was full of chit. i have a buddy (jw5150) that has a terry componet and it took away his knocking. put one on mine and it went away also, don't know that has anything to do with octane and better mileage but i'm getting it. the terry component was put on in sept of 07, bike was bought in july. i also had a sert put when they did my true duals but that did not help, but they also did not have a dyno either.

 

This is what I've always heard about octane vs fuel economy. I'm no expert, this is just my opinion and you can take it for what it's worth but it makes sense to me.

Everything else being equal, there is no significant difference in fuel economy from using fuels with different octane ratings. If you put premium in an engine designed for regular, you will not get more power and you will not get better fuel economy. The only thing you'll be doing is padding the fuel company's pockets with no real advantage to yourself. As someone else stated, octane simply improves the fuels resistance to predetonation. If you've got a higher performance engine that's tuned to take advantage of that with higher compression ratios and more advanced ignition timing, then the premium fuel will give you an advantage in performance and "maybe" fuel economy, assuming you drive in anything close to an economical fashion. Putting premium in an engine designed for regular gas gains you nothing, regardless of what some folks may think. It won't hurt anything but it really doesn't help either!

Actually, with todays fuel injected engines, that's not correct as the FI system will compensate for the increased altitude and keep the fuel mixture pretty much were it's supposed to be. For that matter, the CV carburators they used to put on the bikes will also self compensate a little for changes in altitude. They're not as good as FI but they're way better than the older non-CV style carbs that were around when I first learned how to ride.

The reason an engine doesn't need as much octane at altitude is because with altitude, there is less "air pressure!" Because of the lower pressure, the engine can't pull in as much air at a given throttle opening as it could at sea level. For example, an engine at full throttle and 10,000 feet "above" sea level might only pull as much air in as it would at 2/3's throttle at sea level because of the difference in air pressure. That example is only given as a reference and I have no idea what the difference would really be. Anyway, with a lower effective throttle setting comes less load on the engine and a lower need for octane in the fuel.

FWIW!
Ride Safe,
Steve R.

 

Not sure what this adds to the conversation but, one of my riding buddies has a 06 UC "Screeching Eagle" and runs nothing but 87 octane. While me (08 UC) and another buddy (07 UC) use 91 or 93 octance. The guy on the 06nSE always gets as good or better mileage as we do, and doesn't have any engine knock. I believe he has a Sert with tru duals and AC as his only motor upgrades.

This is an interesting thread, and if all true, is dispelling some myths I have believed for a long time about higher octane fuel.

 

I use 91 most of the time, but have put 89 in at times when 91 was not avaliable. Have noticed better gas mileage with the 89.

 

There are many, many factors that effect fuel economy. How you ride, how the bike is loaded, how the engine is tuned and a thousand other little things that all add up to one result or another.

I used to ride Goldwings (GL1500's) and I rode with a number of other folks that also rode GL1500's. We found, and I later confirmed when I discovered the Goldwing forums, that fuel mileage with those bike often varied greatly depending on the year models. My 93 Aspencade usually ended up to the lower half of what was average, mileage wise. I found out on those forums that mine was getting pretty much what most 93 models usually run. The 96 models seemed to do quite a bit better and the 88, 89, and 90 year models seemed to do worse.

The difference between the best and the worst of us was often close to a gallon of fuel at the end of a 175 mile run. Needless to say, the bottom guy on that totem pole wasn't a happy camper, especially when you consider that these bikes were all essentially identical as far as we could tell but I think Honda was making whatever tweaks they felt the need to make from one year to the next and those tweaks often made significant differences in fuel economy.

FWIW!
Ride Safe,
Steve R.

 

Got a trip planned out west again. I think I will drop down in octane ratings when we get out in the higher elevations. ( Trip = Northern CO - Jackson Hole - Idaho - Bear Tooth Pass, WY and home.) P.S. can't wait to ride across Kansas in late July!!

 

I run mid grade in my RG most of the time these days and see no difference in fuel mileage but it does idle a bit higher so I just tweaked the idle speed down some and all is well .

 

I try to use Molbil 93 octane without ethanol. If I get in a pinch I just fill up with whatever.

 

Well, not to hijack the thread, but now this explanation answers a question I have had for years: When we go out west to the mountains, I thought there was something in the thinner air that increased my mileage. But it is the traditionally lower octane that must be the cause. I go from 33 mpg's here in Houston to 44 in the mountains. I might try this on highway riding where I won't be goosing it too much.......