Why did JH gas up (with a small amount of gas) once at Shell (257th&Stark) and then proceed to go downhill and gas up at Travel Centers on Frontage Road before heading up to Larch Mountain?
I believe I just stumbled onto the answer while driving to coffee this morning. I was driving a Ford Ranger, which is built on the same platform as the Explorer, and it had only 1/8 tank of gas in it. I do not drive the truck all the time, so I figured it had enough gas to where I was going. As I started going down a long hill, my gas gauge went to empty (almost to the point where my gas light should have kicked on). I glanced down and was a little surprised, that my tank was on empty. My first thought was to drive to the nearest gas station and fill up. As I started to get to even ground my gauge slowly floated back to the 1/8 full position. That little jolt, made me think instantly of the JH gassing up twice incident. The fluctuation of a gas tank in a Ford Explorer or Ranger by 1/8 to 1/4 of a tank, while going down hill is extremely common. Having a full tank in the Explorer, you would not see the fluctuation of the gauge.
Here is a forum where other people talk about this fluctuation of the gauge:
http://www.explorerforum.com/forums/showthread.php?t=134398
Evidence tells us that JH gassed up at Shell Gas Station at 9:14am and then he went downhill to Frontage Road to Travel Centers and put more gas in the Explorer a few minutes later. It is odd because JH could have easily gotten gas at Shell and proceeded downhill on 257th and jumped onto the Freeway (I-84) toward Larch Mountain. The reason he probably gassed up a second time, was probably because of the gas tank effect that I described above. Here is why:
1. JH was not familiar with driving WH's Explorer and he didn't know how much gas she had in it.
2. WH was known to keep a small amount of gas in her SUV and had to have help in the past, due to running out of gas. In fact that is how she bonded with CH, during one of her, running out of gas incidents (The Outlook Article)
3. The 302nd Route, which I timed to be around the 23 minutes, goes down 2 hills. This may have triggered her out of gas light or may have shown an empty gauge, since she might have had only 1/8 -1/4 tank of gas in it. The stop sign at 302nd and Stark, sits at a downhill slope. If JH was deciding to either go right to Larch Mountain, or gas up, the downhill effect on the gas gauge forced him to go get gas, even if he had gas in there.
4. When JH gassed up at Shell, he gassed up with a small amount. For example if he had close to an empty tank, and he was forced to put in 10 dollars, that would push the gauge up by 2.56 gallons based on gas at $3.90/Gallon. A 1999 Ford Explorer 4dr has a 21 gallon tank. 21 gallons divided by 8 = 2.625. You need almost 3 gallons of gas to push the gauge up 1/8th of a mark. 10 dollars would give him an appearance of 1/8 more gas until he went right on 257th Street. Once you go right on 257th, it forces you to start driving downhill before you get to the freeway ramp to I-84. I believe JH thought he had put enough gas in, but once he started going downhill the gauge showed him up to 1/4 lower than he thought and he decided to go straight and loop around frontage and put more gas in.
I believe that this lower tank gas effect is what caused him to go back into town to gas up, then when he put in just a little gas, the drive down 257th forced him to abandon hanging a right onto the highway and loop around Frontage Road for more gas.
The intersection on 257th lets you decide to either hang a right onto the Freeway, or go straight and loop around on Frontage. Once you gas up on Frontage, you just go straight and you are back on the Freeway toward Larch Mountain.