Gutless in EV mode

All I have tested in that vein is 30-60 in Ev only (it's faster from 30-60 starting from 30 than starting from zero). After 60, Hv is far more powerful.

 

The wording appears to say that EV City only has the ICE come on when fully depressing the throttle, and that the ICE can come on before that in EV Auto and EU EV. It sounds like EV City is Europe's EV virtually all the time mode, but has that kick down switch to avoid issues like the OP had.

European "Prime" has different EV mode names | Page 3 | PriusChat

Some cities in Europe have EV only sections. The European PiP had a low speed EV mode(IIRC called EV City) to operate in those areas. The regular EV mode did have a lower threshold for turning on the ICE in order to preserve battery charge for use in the city.

 

This is not a trivial question:

When the engine runs, part of the power, ~28%, takes the electrical power path, and the ~72% takes a mechanical path. The computer controlled electrical path provides the eCVT function so the engine runs at near peak efficiency. This is an important part of Prius MPG, maximize operating the engine at peak efficiency regardless of speed or power demand.

Understand the Atkinson cycle means the engine is 'derated' from the peak power the engine generates in an ordinary, 1.8L Toyota. This means the expansion stroke, ~13-to-1, is longer than the effective compression ratio, ~8-to-1. The lower compression ratio is achieved by keeping the intake valve open during the early part of the mechanical compression stroke. This pushes some of the charge back into the manifold. Together the Atkinson engine runs on regular gas while giving close to diesel expansion and efficiency.

In contrast, our BMW i3-REx drives all the time on the 168 hp electric motor. The ~35 hp gas engine drives a generator to sustain the charge at speeds of 70 mph or less. As long as there is battery charge, the car can run full power except when there is a risk of spinning the tires.

Bob Wilson

 

To get mechanical power from the ICE to the wheels, MG1 (the one being driven by the sun pinion in the power split device) has to act as a generator. The only place for this generated power to go is to MG2 or to charge the battery. In high-acceleration, you don't feed it to the battery, you feed it to MG2. So, MG1's 23kW is going to MG2 which means MG2's 53kW rating is split between the 23kW that MG1 provides and the battery, leaving only 30kW to come from the battery. This is over-simplified as the actual numbers depend on speed and losses, but this illustrates the idea.

So, at peak power, 30kW can come from the battery in Hv mode, but in theory 76kW can come from the battery in Ev mode (less, in practice). So the ICE has to produce 46kW (62 HP) to break-even (again, I'm over-simplifying here to illustrate). The ICE needs substantial RPM to produce that much power and it can't run that fast a lower vehicle speeds because of the limitation on how fast MG1 can spin. This is why the car is actually faster accelerating in Ev mode (without the engine's help) below 25mph.