Fueling question...

[shelbydave]

I recall reading on here, and also hearing some people say not to top off the tank at the end of the ride, as you will just boil off some fuel. I have tried not to do this, however, I think after what I saw yesterday, you want at least 1/2 tank or more when you park it hot. We rode out to see some friends yesterday - about 60-70 miles away. When we arrived, I had 2-3 segments showing for fuel level on the LCD. After a few hours visit, I started her back up, and the low fuel light was on! At first I thought it was due to their driveway being on a slight angle, but as we headed down the road, it never went away. So we pulled in for fuel, but by now she was all warmed up to operating temp. When I started filling the tank, not only did I notice the typical fuel vapor, but it appeared to be atomized fuel mist escaping also. So anyhow I started thinking.... I usually fill up when my gauge gets to 2 segments, and while I don't top off then park it hot, I do ride about 15 miles to bring it down about 1/2 gallon. Doing this I have been getting about 32 MPG, while yesterday I got about 28.

It seems to me that you would lose more fuel by parking it with a low tank, than with a full tank as the less fuel will get to the vapor point faster than a full tank. With more fuel in the tank, wouldn't that heat up slower, and give the engine / exhaust a chance to cool off before vaporizing the fuel?

[NoJive]

Interesting. I always wondered where my fuel was going! Anytime I park with a couple bars showing, I almost always come back to a low fuel light.

[flamingobabe]

I try to never park with a full tank when it's hot outside...or look for shade...will fill up after we rest or what ever.and get ready to go again

[boborgera]

I always filled my tank [08] right to the very top, And never had any fuel smell or over flow into the canister,
BUT that said , ''My'' vent system was one of the ''few'' that was working properly,
As in the way it's supposed to work.

[NancysToy]

Interesting. I always wondered where my fuel was going! Anytime I park with a couple bars showing, I almost always come back to a low fuel light.

Simple physics. It may not be vaporizing at all. The colder fuel takes up less volume, so if you are near the light when you park it, in the AM it may well show a light. Sometimes the light will disappear before you get to the gas station, as the fuel heats up again and expands. While the Spyder may boil off some fuel when the cap is opened, it does so much less when it breathes through the vent system and the vapors cant escape the tank readily. You may notice this as the tank hisses from releasing pressure, just as you open the cap.