I added 3 gallons (to fill it up) since gas went down to 2.38 gallon here in East Lansing. Driving range was 470 miles before and 470 afterwards. Added another gallon today and the range did not change. Had always worked in the past. Any ideas?? Thanks,

Fred

 

If it's anything like the Prius (I owned one) you need to add more than a few gallons for it to even realize you filled it.
8 gallons comes to mind but my mind is weakening by the minute.

Edit:

I just reread your post and it seems you are NOT filling the tank but rather just adding a gallon or three here or there and running on the botton forth of the tank. If that's the case I think your issue MIGHT be you need to actually FILL the tank for the computer to reset the estimated range.
This actually makes "some" sense sine there is really no gallon measuring mechanism as you add fuel other than the fuel gage which isn't calibrated in gallons.
The only way the computer would have a KNOW reference point is when you FILL the tank and then does have the ability to count USED gallons.

In short:

FILL THE TANK and the range computation will reset.

 

Thanks, but it seems like I had done this in the past (i.e, add gas before it was even half empty) and it reset, but I'll run the tank down and see what happens.

Fred

 

If I read your first post correctly, you added 3g to FILL the tank, correct? As schmidtj mentioned, the only way that the driving range and fuel mileage sensor gets reset is when you fill the tank all the way to full. So in your case, the display should have reset to your full cruising range. I filled up after killing just half-a-tank, and my displays were reset properly.

 

Even if you filled the tank on the Prius you had to add some minimum number of gallons before it would reset. I THINK that number was 8 gallons but I could be wrong and it could be different for the TCH.
J

 

from what I understood from the manual, I thought that cruising range was based on previous FE and previous tanks, therefore, adding gas wouldn't change it?

I used to drive a grand cherokee (way back when! it was like 10 years ago! don't shoot!) and it had an estimated driving range gauge that updated instantly. So if I gunned it and pulled the speed all the way up for a while, the estimated driving range would plummet. not so with the TCH cruising range, so I looked it up in the manual.

From what I gathered, it seems like they base cruising range off previous FE. So if each tank is better than the last your cruising range should increase with every fill up. Does anyone know the answer?

 

The computation of "Cruising Range" makes use of previous mpg history.
Adding fuel definitely increases your "Cruising Range" but does not
change your historical mpg.
J