ECO button 24/7

I don't think hybrid battery cooling depends on AC use. On the contrary I've seen very little shift in it's temperature, with or without AC. Driving home on cool evenings, ambient temps now around 15C, cabin temp set to 22C, without AC, I still see hybrid battery temp stabilize around 38C.

As far as mpg hit, I've found constant use of AC imposes between 5 and 10 percent penalty.

 

I tried to use ECO for a few weeks, it's just too painful. Without it the car is much better, and there no much loosing mpg, but getting safety. Also no swearing of drivers after you.

 

I can get drivers swearing behind me in Normal, too. The modes are overblown, the control is not that different in any of them. If anything, I was prone to over-gun in ECO, the travel is excessive to the point of being hard to control.

 

ECO takes a while to get used to. Most of the time people tend to accelerate away from a light like they're towing a trailer (slow). I find that my takeoff is very smooth with Eco. When I have power mode on I tend to drive too jerky because the throttle is so sensitive. Overall, I like the differences between each mode. Contrary to what others have said, power mode feels much more responsive on take off than flooring it in Eco mode. If I have to pull out of a driveway into traffic flow I occasionally hit the power mode button.

 

Why would you make a distinction between regen breaking and P&G though? Under normal circumstances you're doing both when driving in the city, unless you're racing from one traffic light to the next. It's semantics I guess. I call the energy stored in the HV battery "free energy", since that energy would be lost in a conventional car.

As for the analogies being used here, I think something like "you buy four and get one for free" is a better one since people with 'normal' cars wouldn't get the free one, i.e. energy stored in the battery.

 

Well, my distinction is "free energy" in terms of active propulsion. Only when the Prius is in EV mode/function are you only using electrical power. So, regenerative braking only gives you "free energy" because it recaptures power you can use in EV mode, but again, the battery in even a PIP only provides X miles of propulsion on a full charge in EV mode only, so overall, it's not all that much power.

P&G, however, is a method for maximizing distance traveled with minimal power/fuel consumption, and it's by far the larger factor in the Prius' fuel efficiency. Eliminate the regenerative braking and how much of an MPG hit would the Prius really take...could be a little...could be a lot. That would be a neat experiment if it could be pulled off without harming the overall system.

 

ECO mode 99% of the time.

 

Same for me. I don't lollygag around at stoplights and stuff in ECO either. ALL the power is still there, you just need to push the pedal farther down is all.

I pop mine into PWR when I'm dicing around in city traffic (rare visits south) or, as you said, pulling out of a busy stop. It's not technically necessary but the quicker throttle response is nice to have in some situations. In day to day driving, I don't need it, or miss it.

 

I've never taken it out of Eco mode, I've never been "left behind" at a traffic light or toll booth, I drive the speed limit, 58ish mpg. What's the problem?

 

The Great White North doesn't see the same temperatures as often as we get closer to the equator. I don't think it gets hot often enough where I am either. I'm thinking Phoenix where the temperature of a locked car outside in the sun is often somewhere near the pits of H-E double hockey sticks. It may be beneficial hybrid battery life to cool down as quickly as you can as you drive.

AC hit is nonexistent for me set at 76-78 degrees F on ECO. I don't track my fuel economy better than 10% so the hit is something less than that.

 

No.
The Prius just uses gas more efficiently
As part of this the Gen 3 a/c is more efficient than a normal car a/c system

 

I only use ECO when the A/C is on or long freeway drive. I prefer Normal for everyday drive.

 

Eco is best to use during Winter Blizzard Conditions here in Michigan , not for better MPG but to help prevent getting stuck , preventing spinning tires ,,, sort of off topic sorry

 

Yeah I've taken it out of ECO mode (a few times); just to see the difference in acceleration. Nice to know I have the power when I need it. But at about months in now, I've just kept it in ECO mode. Works just fine. And yeah, I've seen my mpg average creep up a little bit each fill up. So don't see any reason to pop it out of ECO. Maybe some day when I'm in extra heavy traffic and need extra power to merge, I'll hit that PWR button again Until then, I figure it this way, if it isn't broke, don't mess with it. Average was 51.3 mpg on today's trip around town running errands.

 

In that conventional car the engine is tuned to produce the max horsepower, where the Prius engine is tuned for efficiency, relying on the battery for short bursts of 50 additional HP. The Atkinson cycle engine converts up to 47% of the gasoline into work, the Otto Cycle used by convential cars uses 25% of gasoline's energy. Conventional Brakes regenerate 0% of the rotational energy, while the electric motors recover 30% of the rotational energy in the battery. At very low throttle openings in that conventional car a lot of power (gas) is wasted pulling air through a closed throttle plate, in a Prius lower power demand can mean electric operation, and when the battery is depleted recharging it can mean the engine does more work (driving the wheels and recharging the battery) so the throttle is not as closed.

All the energy comes from Gasoline, the Prius conserves it better than 'conventional' cars.

 

The thing that perplex me is that my Gen 3 prius do better Mpg on Highway (56 Mpg) than on in city busy roads (40 Mpg or less). According to the book, the opposite should occur. One fact I should say, I usually use cruise control on high way.

 

Just to reiterate, you have exactly the same Horsepower in ECO as you have in PWR mode. Those modes do not dial back power to the wheels, they only adjust throttle response.

The modes may adjust some other operating parameters (HVAC for instance) but not Horsepower to the wheels.

Operating modes (ECO, Normal, PWR and EV) - Prius Wiki

 

I'm always in ECO mode. I don't like the throttle response in especially PWR. You only have to look at the pedal and the ICE comes on.
If I need the power, I press the pedal deeper. Usually that means tailgating the person in front of me when pulling away at stop lights, so for me there is no need to use PWR or normal mode.