Depending on where I am, I will usually refuel at 3/4 of a tank. But I frequently ride with folks who need to stop every 100 miles, for one reason or another.
When I pushed mine to the limit it was during the east coast area fuel shortage. To be sure I put 2 ,2 gallon gas cans in sidecar trunk. We did encounter no gas here and there but never go to a point of using the spare fuel.
Last day before heading home we decided find out . Ran it until it warn Low ignored that. Kept going until all it showed was ----.
It had been that way a while. Stopped near where we were stay and filled up 5.7 I doubt it would have gone much farther. Sidecar sucks fuel more in head wind I never pushed my luck knowing 35MPG can turn into 20 mpg real fast.
That was a deciding factor adding 4 gallon AUX tank to the Trike build.
So I ran mine out of gas once. Saw the low range warning and everything and somehow ignored it - was in my head thinking about whatever.
Anyway, the bike went about another 35 miles before leaving me on the side of the road.
A friend filled a plastic coke bottle with 12 ounces of fuel (it's what he could get apparently) and I road that 7 miles to a gas station. Put in 6.037 gallons.
So on my bike, after the low range warning, I have about a gallon left in the tank typically.
Electric fuel pumps work hard and generate heat. Normally that heat dissipates into the fuel surrounding the pump. When the fuel level gets low, the pump is no longer bathed in fuel and it gets hot. This happening once in a while is not a problem but habitually running down to the last 10 miles will repeatedly allow the pump to get hot. If you save enough time by not buying gas more often than absolutely necessary, you might save enough time to replace that worn out pump more often than most other riders....providing the failure happens at home.
Range is estimated based upon calculated running average fuel economy and fuel remaining in the tank. If you were riding on flat ground with fixed speed and fixed drag/load it would likely be dead nuts accurate.
However... If you were riding at fixed speed with fixed drag/load for the first five gallons and you then pick up a passenger and continue at higher speed going uphill the estimated range will be less than what is calculated and presented. Conversely if you dump a passenger and continue at lower speed while going downhill the estimated range will be more than what is calculated and presented.
Elevation, Temperature, Relative Humidity, etc. also play into actual realized remaining range. High elevation, high temperature, and high relative humidity reduce engine power and efficiency and therefore reduce remaining range.
I have left my house for a longish ride with the estimated range not going down for many miles due to slow steady-state riding along the way. Conversely I have left my house riding hard and the estimated range goes down quickly due to being heavy on the throttle.
In general the ECM doe a pretty good job in my opinion. I wonder if @Steve Cole might have something to say baout all this?
When riding through New Mexico / Arizona towards Vegas one year, my Ultra and a friend's Goldwing were getting similar mileage. There are some looooong distances between fuel stops and it seemed that when the GPS showed a gas station en route, it was closed or missing. Every time we topped a hill hopeful for a break, we were met with another lonely stretch of shimmeringly hot highway, dead straight as far as we could see.
It got to the point I wondered why bikes even have a gas guage. Mine had shown out of fuel for so long it was silly. My bike was stumbling as we approached what I knew would be my last hill, I was having to shake the bike side to side to get it to run. We crested that last hill and there it was, like a luxurious miracle in the desert - a gas station. That was the best feeling ever.
It took longer than usual for the computer to calibrate and show miles remaining after gassing up, but no harm long-term.
08-15-2024 | 10:41 AM
