Speed Kills ( gas mileage that is)
:agree:
Exactly, pushing a barn door down the road takes a lot more power than slicing through the air with a knife. It is all about the drag...aerodynamic for the most part, but friction enters into it too.
I have a 2013 RTS-SE5. Overall I get about 27-28 mpg. I think that is comparable to most motorcycles. I did a 300 mile trip this weekend with my Harley buddies and we all had about the same 'legs.' Stopped for fuel pretty much in sync.
There are exceptions to mpg vs engine size. I traded a Victory Vision Tour in for the Spyder. It got 40-45 mpg pretty consistently - that big 1731 CC engine just loafed at 2,000 rpm and it had a true overdrive. Its legs were way longer than my butt enjoyed. LOL My corvette which is both aero slick and drops to 1700 rpm at 75 mph also gets a counter-intuitive 28-30 mpg at 75+ mph. I love poking the Honda drivers with that one. I guess I am mean.
What everyone has been saying is right on.
What uses up energy?
1. Weight is not really a big factor - in a perfect world once you accelerated you could shut off the engine and go forever. (Like space vehicles do now in a near perfect vacuum)
2. Friction uses up energy - there are two kinds of friction - rolling and internal. Rolling friction is from your tire grip, bearings, etc. all those things we lubricate to keep moving.
3. Internal friction - all the above applies to inside the engine it has internal friction from all its moving parts (this goes down some after breakin hence mpg gain)
4. Get really picky and you can also add the power needed to produce electricity from the magneto - that ain't free either :sour:
5. The biggest culprit is what we pilots call parasitic drag. All that frontal area (more than a motorcycle - two 'open' wheels , the windshield and the rider(s) all contribute. I don't know what the coefficient of drag is for the Spyder but i am sure it is not .23 +/- like my corvette and most newer cars. The really bad news (speed kills) is that the parasitic drag goes up with the square of the velocity change. So drag at 60 mph is 4 times what it is at 30. That is what kills the top end on a vehicle at some point drag = available power and there ain't no mo' push. LOL
NancysToy and the others are correct in rpm range too. The clutch does not fully engage (stall) until 3200 rpm +/- so you are wasting fuel and wearing the clutch both if you are not above that. This engine makes peak power around 5,000 rpm so everyone is correct there as well. peak power implies best volumetric efficiency so best fuel burn to power ratio around that range.
When you go to the dealer for service BUDS will give you a read out of how much time you spent in various rpm ranges. So if you are 'lugging' and not staying where this engine is happiest 4000-6000 rpm the BUDS system will 'rat you out' - ask me how I know lol.
Bottom line just have fun and don't worry about the mpg.