Told you your tank burps. It only matters for what you consider full and where you think you are adding to. No manufacturer says to fill any tank to the top to allow room for expansion. All I do is fill full, wiggle it a time or two, done. That's usually before a ride not after.

Finally did tank on the trike... 32 mpg normal driving. Full tank => empty tank. Do that over several tanks, and differences on what you think is full averages out. Full tank, to empty tank. Miles/gas in. All the dinky low milage tests are not telling you anything accurate. Every error in filling to different level at different temp with small amounts is magnified.

Do several full tanks, burp it, don't burp it, but do it the same... then see how accurate your measurement is to the computer... You can make your own correction factor.... Or just use you trip computer for distances to turns or route, and not trip on what it tells you mpg is.

 

Yes, I agree that the most accurate measurement of an individual owner's MPG is achieved by:
- simply starting with a full fuel tank (filled via whatever method you want to use, as long as you are reasonably consistent on the FIRST and LAST fill),
- zeroing the trip info screen by choosing a new far-away destination that you don't intend to actually visit
- refilling the tank whenever you feel like doing so (if you are interested in ONLY getting the overall MPG for the entire test duration)
- when ready to stop the longterm test, fill up PRECISELY the same way you filled at the start of the test (if you want best possible accuracy)
- Calculate the MPG based on the TOTAL gallons you pit into the tank after starting the test
- Compare that to the MPG claimed by the HD Trip Info Screen, and decide which one you want to believe if they are different.

The flaw in that plan though is that it only gives you your average MPG for the entire test period. No breakdown by speed, which is important if your speeds and traffic situaitons during the tets period are not representative of your normal, OR if your normal is a mix of city, suburban and highway, but you are planning a long multi-day hgihway trip with minimal city or subrban riding, and at speeds that are not the same as during your test. It alos does not tell you how far you can go before running out of gas if you find yourself on a segment of highway you are not familiar with that has few gas stations.

I was hoping to get more detailed info that I could use to do some long trip planning, and to make speed versus MPG decisions.

Jim G

 

"I was hoping to get more detailed info that I could use to do some long trip planning, and to make speed versus MPG decisions."

Let's hope that your research doesn't conclude that a sustained 30 MPH is best. Or, 95 MPH for that matter.

John

 

Starting in 2014 Harley began using a different filler neck on the Touring and Trike Models. Not sure about Softails, Dynas (RIP) and Sportsters (RIP).

With the change of the filler neck, the fuel gauges are much more accurate, or should I say, less inaccurate than they were before 2014.

The consequence of changing this is that the bike or trike needs to be rocked side to side to let trapped air escape and more fuel to go in. This applies, whether you have a tank lift or not.

On my Trike I normally can fit over 1/4 gallon more in by moving it side to side and letting that trapped air escape, WITHOUT it be overfilled.

Kevin

 

With or without a tank lift, there is plenty of room for expansion if you fill to the bottom the the neck...and to get it truly to the bottom of the neck it needs to be burped. Check out the images below to see how much room there is for expansion.








Kevin

 

I’ve been shaking my handlebars ever time I fill up.
I simply do this to get more gas in it because the Trike only gets 29 to 31 mpg in real life.

When shaking bars doesn’t lower fuel any more you finally have a full tank.
Mike

 

The admittedly highly imperfect testing that I have been able to do so far, with the Info screen and manual fills often disagreeing more than "a little", suggests that 50 to 55 mph is the right speed if you don't know how far to the next (open) gas station, IF that is a safe speed on the road you happen to be on. But on some roads, that will get you run over by angry cagers and semi truck drivers, especially in some regions where the speed limits are viewed as "suggestions".

Jim G

 

Thank-you, Kevin. Good to know, and since I did not know until the other day about "burping, rocking, or wiggling" being an integral aprt of an HD tank filling, This is likely a game changer for my testing efforts. I know that the hD OEM suspension is "cost driven & limited" in terms of on-the-road performance. Does it atv least enthusisastically support "burping, rocking, or wiggling"?

Jim G

 

Again, Thanks, Kevin. I had no idea there was THAT much empty air space in our tanks.

Jim G

 

I am dying to see that text in an HD user manual! Somehow, it seems right for an HD manual.

Jim G