Prime SE owners: anyone driven to empty ?

Never let pirus run that low
Don’t do it you will be sorry

 

I ran my Gen 3 to the point of the gas engine stopping more than once. As a test, when I was coming home from a vacation in BC, my refuel light came on at Field BC, and I hit the trip meter. I nearly got home, but the engine quit when the trip meter said 180 kms. I could have probably limped along on electric power for another 20 kms, at about 30 kph max, but that's when I elected to put 10 L of gasoline in the tank. It started and ran normally, and it easily made it to the next gas station.

Another time, I had been running around town on Empty, not paying attention, and the engine quit. I ran for a while on electric, but I stopped a bit short of a gas station. I had to walk for a jerry can. Once again, it started and ran normally afterwards.

I honestly can't imagine that this was damaging to the vehicle in any way.

I have tried similar tests with my Gen 5, but so far the car hasn't run out of gas.

 

doesn't the manual state how many gallons are in reserve? i think my gen 3 said 2g or so when the refuel light comes on.
i ran my gen 2 out of gas by accident. drove on electric until it shut down and the dash lit up.
added a few gallons and she fired right up

 

@bwilson4web experimented with that in his Gen 4 Prime. I don’t understand why you would do that, but his conclusion was that the car eventually refuses to drive if you keep doing that.

 

On my Gen 5, it shows the range to empty. Once it reaches zero, it resets again to 40 kms. (with the warning light on). Once that depletes, it simply says, "refuel." So far, I've always got to a gas station before it stopped running.

 

I'm not sorry at all. I wanted to determine the actual range.

 

The G5 is specced to have 6.0 L / 1.7 US gallons of fuel remaining when the "low fuel" warning appears. That should easily be good for at least 100 km / 60 miles of HV. There's no direct spec of where "zero range" is, but you can infer it from that.

This weekend I drove down to 10km left on EV range and "Refuel" (what it says after reaching zero) on the fuel range.

Low fuel warning had come on with 35km left on the fuel range - I drove on maybe 15km past "refuel", but not sure how much of that was EV.

When filling up it took 35 L (9.2 US gal), suggesting 5 L (1.3 US gal) left in the tank. More than I expected - suggests the low fuel indication being a bit conservative, or maybe the pump just cut off early.

Based on a conservative 6.0 L / 100km, if the "low fuel" comes on at 35km, you could expect at least 65 km of HV past "refuel"/zero range.

 

You don't need to run out of of the fuel to determine the range. You know the average mpg and the fuel-tank capacity given by Toyota and combined with the gas-station receipts (how much gas left in the tank), you have all the info you need.

 

I prefer my way.
It's more accurate.

 

Think about 2 things low fuel or out off gas
Fuel pump needs to be in fuel to stay cool or overheat
Cat Converter plus damage exhaust system
Up to you all

 

Which isn't an accurate measure of how far the car can go in HV mode alone, if there was grid charge left. An owner has seen that the car will use some of that grid charge in HV mode for better efficiency.

 

Think about this: If the engine's not running,
there's nothing to overheat the fuel pump.

 

Are you sure they said "past zero miles" or was it past the low fuel warning, which happens considerably earlier?

The low fuel warning in the RAV4 is specced as 8.3 L (2.2 US gallons). 100 miles past low fuel would hence require 45 US mpg - possible, but far from guaranteed.

Given the smaller 6.0 L (1.7 US gallons) value for the Prius, you're not realistically going to get 100 miles in HV past low fuel. As I said above, 60 miles or 100km should be easily achievable.

 

With our ‘58 VW bug my dad would take off the gas cap (under the hood) and check how much gas was left, with a stick. There was no gas gauge. There was a last minute recourse: when the engine started to sputter, you could reach down and rotate this lever on the firewall, which release an emergency reserve. Gives you a different perspective.

Now, you buy a $40k vehicle, with a gas gauge and this miles-to-empty jazz, and still you want to run it down till there’s about about a tea cup of dregs sloshing around in there.

 

Correct.

One of the first owners here was trying to test the hybrid fuel economy. They did this by putting the car into HV mode with charge left. The results were unexpected, too high IIRC. Over an entire tank, the EV charge display did start to drop. That display, nor the range estimate, is not accurate enough to let the driver know how much the battery was depleted. Then just giving a hybrid more capacity to use will improve fuel economy with the balance of the charge averaging the same.

A Prius PHV will go about 85 miles on 1.7 gallons by the EPA combined rating. I would not plan on it going farther than after the low fuel light came on.

I agree that they were likely reporting range from low fuel light. My Toyotas stopped displaying a distance to empty figure once that came on. Easy to mistakenly report that as zero miles.

 

I was able to do my test by carrying a 10L fuel container. Something I learned to do years ago (from bitter experience). It may not be strictly legal to do so, but I'll chance the consequences against the peace of mind I get from having it in my car.