Question about running with no gas

It generally is unless you run out of fuel. There is no speed-limiting mechanism per se for battery power; it's just that the ICE generally lights at >40 MPH.

Even with fuel, there are limited conditions under which the car may run on battery power, although the ICE is still spinning with no fuel from the injectors. I've seen instances of higher-speed electric-only propulsion when HV battery charge is near 80% (eight green bars).

 

I know that in this case you probably wouldn't have made it to a gas station anyway, but if you're really trying to get to a gas station or a phone or something then you'll generally go a lot further if you can keep the speed down at about 20 to 30 mph.

At about 41 or 42 mph it starts turning the ICE, even if you are running on batteries alone, and this (along with wind resistance) will reduce your range.

 

Heretical Mode - GreenHybrid - Hybrid Cars

Yup, there's way more to the HSD than should legally be allowed to know.

 

Hi Hill. Running all electric at greater than 42mph is not what they refer to as Heretical Mode.

Heretical Mode is just where MG1 operates as a motor and MG2 as a generator (with the ICE also inputting power of course). This appears to be heretical from a engineering/physics perspective as you're putting in electrical power at MG1, passing the power through a lossy device (the transmission power split device) and then recovering electrical power from the output. At first sight it doesn't seem to make any good sense, however it does allow for really low ICE revs at moderate speed in some instances where only low output power is required. Kind of like an electric overdrive.

 

I have another question under this heading, what is the parameter that the car uses to actually stop trying to turn over the engine when there is no more fuel. I have not read of accounts that the engine runs rough, it generally just doesn't run any more. Is it safer -concerning the life of the fuel pump- to run out of gas in the prius that the average car? That is, is the fuel pump not trying to pump in the empty tank?

I remember reading accounts of people testing for tank range by running empty after the low fuel pip, and personally haven't tried it- yet .

 

yea but aren't 41+mph speeds where one benefits from it (mpg wise) the most?

 

Yeah I was wondering the same thing. It must somehow sense that it's empty.

 

Yes I would think so.

BTW. I think the mode that best describes the OP's situation (full electric over 42 MPH) is often what's referred to as "warp stealth" mode.