Circling back, I think I figured it out. Tank capacity = 17.2 gallons.

2.6 gallons for low fuel light as a usable reserve (Page 519 of the manual).

Another 2.6 gallons that unusable/kept to prevent you from running below the amount to run the hybrid system on normal inclines. Page 78 of the manual.

17.2 - 2.6 - 2.6 = 12 gallons for the ‘E’ indication.

Time after time after time we refuel and it only takes 12.5-ish gallons. So the usable tank capacity (with the refuel light on) should be ~14.6 gallons before it fully shuts down as it protects that very last 2.6 gallons. I had thought the OM was saying that these are the SAME 2.6 gallons. I now believe they are separate.

That’s my theory.

And, 14.6 gallons (usable) x 35 MPG = 511 range, which is in the range of what ours indicates when refilled.

 

What ever the explanation is, the dealers are clueless. The only thing they tell us is everything is functioning properly.

 

Unfortunately for the consumer, dealers are programmed to say such things, along with "They all do that".

 

And "We've never seen that before".

 

Yeah, "We've never seen that before " Oh? What about this TSB I printed up? "Oh right, now I remember."

 

Too funny! It is absolutely true, as well. I've done this one myself.

 

i am not so sure that the 2.6 gallons is not inclusive in the low fuel indicator amount from the manual but hey , who knows , maybe it is over 5 gallons

 

We need a volunteer willing to test how many miles you can go beyond '0 to empty' and to report back how badly the RX hybrid gets bricked when it is truly out of fuel.. Please report back here

 

All Toyota and Lexus systems are programmed to attempt to start the gasoline engine when the battery reaches its "recharge threshold." If the engine does not start after three attempts, the system shuts down and requires a technician to reset a fault code before the vehicle can get moving again, even if fuel is added.

 

If you have a scan tool you can reset it yourself.

 

The RAV4 prime manual has the same kind of language. Some owners have run them to empty and found that they hold the rated capacity at that point. I'm planning to run our RX450h+ to empty to see if the same holds true, but it will probably be a while before the tank get that low. Of course, I'd be more conservative if I didn't have the EV capability.

 

2.6 gallons sounds like an awfully large reserve.

 

Good info to know. I'm driving my first long trip in 2 weeks. NYC to Central FL by way of Central Georgia.

 

i am not so sure the manual isn’t referring to the same 2.6 gallons on both pages

 

So I got a little lost here. Has anyone actually determined, for my RX350h, how many gallons or approx miles are left once the "low fuel" light comes on. What's the "summary version" of what needs to go thru my head when that light comes on? (As in, "oh, I have about 30 miles to find gas").