So. I just finished my first tank on the TCH (loaded, with Navi). This is a fill-up from the dealer and I think it wasn't a full tank. I had something interesting happen....

The Navi screen trip computer said I had 13 miles left on the tank. The needle on the Fuel Gage (analog display) said I had about 1/16th of a gallon (or perhaps a bit more) and the orange fuel light was on. I had been steadily down-ticking throughout the whole tank.

I was .5 miles away from the end of the trip when the analog gague suddenly went to ZERO and the Navi-trip-computer said Range = Zero. I was on electric motor at the time, and was not using gas. I was driving on a flat, level surface. I thought maybe it was an error...wated a half a mile...nothing changed. So, I turned and went directly to the gas station. I made it.

When I filled up, it only filled up with 14.533. I thought there might be an error so I topped it off to be sure. (I don't normally and won't normally top-off, but I was pretty sure the tank was 17.2 gallons, so I couldn't figure out why the computer and the analog gague were both showing 0 gas when I still had 2.5 gallons left in the tank.

After I filled it up it went to full and the display showed 5xx miles range.

I've never had this happen in any other car. (Including my wife's Acura MDX which has a similar electronic trip computer and several analog gagues in other cars I've owned.)

Some questions:
1. Anyone else have this happen?
2. I'm going to wait to run through another tank. If it happens again, I'm taking it to the dealer. Doesn't seem normal. Sounds like a busted gague. Anyone have any thoughts on whether this is normal?
3. What's the deal with the 14.55 gallons at the station? Did I have 2.5 gallons left?
4. I'd like to input my first tank into the database. I only have what the computer reported.....the dash board display said 37.7 MPG; the graph on the navi display said 36.9. (So I can't calculate manually.) I think the reason they're different is the graph didn't reset with the tank, so I'm going to go with the dash board display and input 37.7. Does that sound like the right thing to do? Do these oddities indicate I should avoid inputting the tank?

Any other thoughts welcome.

Thank you. (And I'll report back on my second tank after about 3 weeks when I go through the 500 miles! :>)

This has been covered in other forums (and elsewhere in this one, also). The gas guages are VERY conservative. You said that the gauge showed 1/16 gallon left (I assume that you mean 1/16 of a tank left) - when you hit "E" on the gauge, there seems to be about 2-3 gallons left in the tank.

Look at this forum posting (someone actually ran their TCH out of gas on purpose):

http://townhall-talk.edmunds.com/WebX?14@@.efeaca1/2193

Keep in mind that running these cars out of gas and continuing to drive on battery power is NOT A GOOD IDEA!

The dealer will most likely tell you that this is normal. I wouldn't waste my time to bring it in.

Yup, here's another post on that:
http://www.greenhybrid.com/discuss/c...ange.7846.html

Thanks for the cross references. I should have searched better.

From reading the other posts it sounds like this issue is normal--though I will say it is odd, nevertheless.

Do people typically drive another 40-50 miles after hitting empty? Or are folks being conservative and fueling up when it hits zero?

I'm inclined to wait 50 miles after it hits zero, myself. If it has 2.5 gallons left, even if I'm getting 25 MPG, it should still have plenty of gas.

Thoughts?

Also...I'd like to input my first tank into the database. I only have what the computer reported.....the dash board display said 37.7 MPG; the graph on the navi display said 36.9. (So I can't calculate manually.) I think the reason they're different is the graph didn't reset with the tank (when the dealer filled it up), so I'm going to go with the dash board display and input 37.7. Does that sound like the right thing to do?

Thanks for the assistance.

When the low-fuel light comes on, typically around 14.2 - 14.5 gallons have been used, which means there are 2.5 to 3 gallons remaining. Once I drove 65 miles after the light went off, and filling up the tank just took 16.1 gallons, so there were 1.1 gallons remaining (though it would be unwise to use them, of course).

You can take the miles you traveled and divide by the gallons you used to fill up and calculate your mileage from that number.

Normally, that would work fine. But, here, my dealer filled up the first tank (not me), and I don't know whether he reset the tripodometer or the graph display when he filled it up (sort of doubt it). He also may not have filled the tank completely--when I received it the car had 6 miles on it, but the tank was slightly less than full [corrected from "empty"]. So I'm still thinking the best way to go here is either to ignore the first tank altogether or to just go with what it says on the computer display. ?

He also may not have filled the tank completely--when I received it the car had 6 miles on it, but the tank was slightly less than empty.

I assume you meant slightly less than "full" since the dealer is supposed to give you a full tank.

The first tank is really "iffy" on a manual calculation. On a fill up, just 1 quart of gas can mean a huge difference in the mpg calculation. I'm guessing my dealer stopped pumping gas when it kicked off and that means it was pretty full as all I've ever been able to do after that is squeeze in a few more tenths when I fill up. However some dealers may not even take it to the "kick off" and you may be short a gallon or two. You'll know as soon as you fill up and check the milage against the computer.

So it sounds like just use the computer for calculations and enter that into the database?

OK, I'm going to be blunt. Why in this world do people need to test their low fuel level indicators? It's probably not as important as the old days prior to fuel injection and computer controls, but I always go with the rule of thumb to fill up when the gauge hits 1/4 full. If after a few fill ups I find that 1/4 on the gauge is closer to 3/8 or 1/2 then I'll let it go a little longer. But on my first tank with a brand new car, not knowing how the fuel gauge is calibrated it is not a wise move to have the miles remaining indicator going down to 13 miles. This is not exact science, it's an estimate. Running out of fuel is not recommended by Toyota, and there's probably a reason for it.

Sorry for my rant. Just don't want to see people doing harm to their cars to see who can go the furthest between fill-ups. Over 500 miles is plenty for me.