The fuel mileage on these bikes is very susceptible to minor variations in road, weather and riding conditions, fuel, etc. On a recent 10,000 mile trip my mileage was all over the place ranging from 29.5 to 44.3 with an overall average of 37.2. I attribute very little of that variation to different fill levels at each gas stop as I was very meticulous in filling it to the same level each time.

 

With fluctuations like that, and with what I'm seeing in the fluctuating fuel consumption, it is nearly imposible to plan fuel stops accordingly because your range may be 220 miles on a tank, or only 148 miles on a 5 gallon tank, depending on its mood.

In these parts out West, the next town and fuel stop could be out of reach if your bike decides to go into the 30 MPG setting for whatever reason, and filling up every 100 miles like we used to with the 3 gallon tanks is a pain in the ***.

Looks like a couple of gas cans for my saddlebags will be on order soon to deal with this moody EFI system.

Is there a setting, or settings, that can be swiitch on/off to give a more consistant and predictable MPG. On the 2003, the EFI system does not have the O2 sensors in the pipes, does it use barometric pressure to determine altitude, eg Sea level to Rocky Mt elevations ?

 

Not exactly... but you could almost consider your right wrist as a switch of some sorts. The difference in fuel mileage between running 65-70 mph vs. 85-90 mph is significant. Slow down a bit if you are squeezing fuel to the next stop. On my trip my average cruising speed (interstates) was at 10 mph over the limit. In some places that means I was running 90 mph.

This variation is not really based on any "mood" of the EFI. It's directly attributable to speed, altitude, and the loads the engine is experiencing, i.e., wind speed and direction, uphill, downhill, etc.

 

the efi senses pressure in the throttle body, the pressure which will vary with air density due to altitude or temp changes

Mike

 

Well, perhaps that would explain why some of the folks I ride with who have 110's and 88's don't leave me and my old 80" EVO in the dust.

Because, if they punched it, they would run out of fuel before the next town. They ride like grand-ma on vacation looking for parking, if the speed limit is 65 mph they ride 60 mph. Slow....

Now I'm one of them with a big bore, 95" twin cam, XXX HP and YYY Torgue, and I have to run it slower than my old EVO to get the same MPG, or mostly even worse.

Anyway, that big-*** drive-in movie size screen of a windshield is being replaced with a 7" on the batwing, that should cut down in the wind resistance...and will go from there.

Its still questionable, why I would get 34 MPG, then 44 MPG with no real change to hi-way speed or driving, that's a huge difference.

 

Did you run with the cruise on while getting better mileage? I rode my brothers bike out to Ga for him from Phx. First day I did not use the cruise ran about 35mpg. Next day ran with the cruise most of the day and ran about 45mpg at the same speeds. Determined my wrist was not as efficient as the cruise.

 

Alot of variables mentioned above, so here is another.
Fuel itself makes a difference.
I have never kept track in any bike I have owned, Until the the price reaches $20 a gallon, don't care.
I do know in my pickup if I run 87 or 89 which say @ pump (may contain up to 10% ethanol) I get 16 , and if I fill with 92, premium, NO ethanol added, I get 19.2 (both averaged).

 

Yes, that's it.

I was getting 35 MPG to 37 MPG without the cruise, then started using the cruise control and suddenly got 44 MPG on one fill up and 42 MPG the next.

Possibly a combination of a higher octane with less ethanol (I didn't pay strict attention to this.) since it wasn't pinging I wasn't using the higher octane gasoline, mostly used the mid-grade stuff (87 octane).