Poor acceleration, high engine speed when battery is low.

ECO mode produces absolutely no power decrease whatsoever. The power difference you feel is entirely in the 'touch and feel' portion of the user interface, specifically in how the gas pedal movement is interpreted by an ECU.

For an ideal operator -- instantaneous reaction time, perfect dexterity, infinite patience -- all modes should produce the same MPG, apart from some minor differences related to climate control, cruise control, and engine auto-shutdown. When combined with real human limitations, most people will do best with ECO, some with PWR, some with Normal, and some will actually get the same in all modes.

Use whatever mode you like.

 

"Switch to ‘ECO’ Drive mode and the car will automatically manage fuel inputs and optimise the air conditioning system for maximum fuel efficiency."

aka manage or reduce throttle response.

resource: Toyota Prius c features performance 'ECO' and 'EV' drive modes


"ECO mode reduces throttle response to help you accelerate slowly and smoothly. It also modifies air conditioning response to reduce the drain on engine power. Driving in this mode will improve fuel economy. To operate, press the Eco Mode button behind the shift lever."

This is in response to the 2014 Toyota Corolla (non-hybrid), but the concept is the same.

resource: How does ECO mode change my 2014 Corolla driving experience and how do I operate it?

 

I think you are reading too much into a marketing blurb. "Fuel Inputs" here basically means "how far the accelerator pedal has been pushed", and "throttle response" means the same thing. In eco mode you have to push the pedal further to get the same reaction from the engine control computer, but that reaction is the same as it is when you're not in eco mode. In other words, the fuel economy derives not from managing the engine differently, but from managing the driver differently. The driver is used to pushing the throttle down a certain amount and in eco mode that same pedal displacement produces less power - hence more fuel economy.

 

As Sean pointed out, those statements are just fancier and fluffier marketing ways to say the same things I did. My version is distilled from much older Toyota information posted during the 2010 rollout, and from PC folks who were invited to talk to the actual Prius engineers during the introduction events.

 

I stand corrected, thanks guys!

I know when you hammer the pedal in eco mode it will pick up pretty quick when merging onto the freeway.

I suppose what I should have said initially is that I don't like the decreased throttle response through the acceleration range, aside from pinning it, while in Eco mode as the vehicle responds lethargically IMHO.

That being said I am sure there are a ton of people who enjoy Eco mode almost exclusively. I suppose the mode you choose will depend on your driving style and preference

 

Yup. While there is a small difference from climate control and cruise control, the major thing is just different tuning of the user interface. Pick whichever one suits you.

 

Hammering the motor on a daily basis is not the best way to get the most life out of the motor, I barely push on the gas, averge 55 MPG, and feel like it is fast enough! This is a hybrid, not a Civic and it will never feel as powerful as a Civic. You need to think about why you want a Hybrid? If your looking for a fast car, this is not it.