Fuel gauge extremely nonlinear!

<div class='quotetop'>QUOTE(ScottY\";p=\"98606)</div>

That's been true of every car I've owned. My Ford Explorer, for instance, would show the fuel needle pegged well above the "F" after filling up. After a couple of days, it would finally move off the peg and start slowly moving towards half full. Below half full, it would pick up speed.

It's probably been the same on every other car you've owned, but you just didn't pay close attention.

In my other cars, when I looked at the gas guage, all I cared about was whether it was above 1/4 of a tank or below. Below 1/4 meant I needed to get gas that day. Above 1/4 meant I could worry about getting gas another day.

 

Every car's fuel gauge is non-linear, Yes, that is done so people fear running out of fuel as they see the gauge drop faster at the end and they go get gas and slower at the beggining so they think they are getting better fuel economy. However, almost every other car has only that one non-linear element since the fuel tanks is a constant size.

due to the bladder in the Prius the car has a variable volume fuel cell (hey maybe they could put those letters on the car so that people think its super special that the fuel tank constantly changes volume hmmm "the 2006 Prius now with VVFC!) Get used to it!

This is really the only real gripe with the car, as it is a design issue that Toyota should have dealt with, as they apparently have in the RX which does not have this system.

 

<div class='quotetop'>QUOTE(Devil's Advocate\";p=\"98660)</div>

Here's the explanation from Car Talk

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Dear Tom and Ray:

Why do different car manufacturers set such different standards on their gas gauges? In our old Buick, when the needle hit the yellow area, you had to be driving into a gas station with enough momentum to reach the pumps or you were in trouble. On our new Taurus, you can drive for another week. Also, why does the first half of the tank take so long to run out while the second half flies. On my Blazer, I find that I can get about 220 miles on a tank before the gauge hits the half way mark. But the second half of the tank is gone within another 150 miles. Finally, what's an easy way to learn the real size of your gas tank? Harry

Tom: Good questions, Harry. The reason the gauge says empty before the tank is actually empty is that the manufacturers don't trust you. They build in a little "wiggle-room" to make sure you don't actually run out of gas.

Ray: In the old days, it didn't matter. You ran out of gas? Tough! But modern cars have fuel pumps that are submerged inside their gas tanks. And since the gasoline acts as their lubricant and coolant, you can do damage to the fuel pump if you run the tank dry. So the manufacturers make sure that even when the gauge reads empty, you still have a little gas left.

Tom: That's also why the first half of the tank appears to last longer than the second half of the tank. It's because you never actually USE all of the second half of the tank. When the needle gets to empty, there's still gasoline in there. And, as we just explained, it's there for a good reason.

Ray: So, given this information, what's an easy way to determine the actual size of your gas tank? Well, you sound like the curious fellow, Harry. I'm sure that our explanation has merely piqued your interest. And I know you're going to run the tank in your Taurus down past empty, just to see how much gas is really in there.

Tom: And that's how you'll find out how big the tank is. When you run out of gas, see how much it takes to fill it back up. Then you can sit down and think about your new-found information... while they're putting in your new fuel pump.

 

<div class='quotetop'>QUOTE(ScottY\";p=\"98710)</div>

I'm thinking of putting in a PC case fan to replace the center-speaker in order to cool that hidden area. Just need to find a 5V rail to hook up to.

It hasn't melted my cd-rws yet, but I worry, and I figure things inside will break down faster esp during the day under all that sun. If it feels hot, it's over 90F; bad for electronics in the long run.

 

Cars are designed to expect to be reliable at 120 degrees, as it could easily get that hot on a summer day with the car left alone with windows closed. CDs are fairly reliable there too.
Don't sweat it. Pun originally not intended, but hey, it works.