ECO Mode vs. "Normal" Mode MPG

I must say going from a long term ECO mode to normal, apart from the obvious sharpening of the throttle response, I found the engine was more willing to come on when you're moving from the traffic lights than ECO mode.

 

I'm an "eco mode" all the time guy. But yesterday it was quite warm and muggy so i wanted the extra AC power and put it in Normal mode. I filled up with gas and drove from the valley to Vancouver in "stop and go" freeway traffic. The AC was freezing cold (amazing!) and the fuel economy was at 3.8L/62mpg for the trip. Speed was from 110kph in the good areas down to crawling heavy traffic. I like the different feeling of power in normal mode.

 

I agree Tideland. I would much rather drive in "normal" mode, but prefer ECO on those short trips to save battery power.

 

My rule of thumb for elevation suggests that altitude loss saved only 1.7 liters, or 0.2L/100km for an 840 km trip. Kamloops isn't very high, so 75% of the altitude savings had already happened by the point. So most of that result is skill under the road conditions, not the free ride of elevation change.

I haven't yet had my Prius on the Coquihalla, but seem to remember hills too steep for fuel efficient descents.

 

We switched over to Normal mode, about half way into a run from Vancouver to (Vancouver Island's) Long Beach, this last weekend. Mileage did not seem to suffer: have yet to tank up since getting back, and the in-dash is sitting at 4.1 (likely around 4.4 calc'd.). On an earlier trip up to Williams Lake we stayed almost esclusively in ECO, and achieved about the same.

I noticed some instances in Normal mode where the gas consumption display meter seemed to stick around 3~4 blips up from the bottom (very good metric mileage), and even a little extra gas pedal pressure did nothing to it.

 

I just got my Prius for less than a month. After experimenting with the driving modes, I prefer to go with NORMAL most of the time. It is only when I take short trips(less than 10km) that I switch to ECO mode.

About P&G technique, I find it take my mind away from enjoying the journey and conversation with passengers. I find the habit of maintaining smooth flow can still achieve reasonable mileage even at NORMAL mode.

 

I always use ECO mode because I just like "low gain" throttle response. It is good for driving smoothly.

I did a little experimenting to make sure that things work the same in all modes if you "floor it." I found that the car gives maximum possible acceleration in all modes when floored, a good thing when passing on two lane roads.

I suspect if I checked gas mileage using the different modes, I wouldn't be able to measure the difference. In normal or power modes, I just wouldn't push the pedal down as far in normal driving. FWIW, my "lifetime" average is about 47 mpg.

 

That's been my experience, the only downside to eco mode I've noticed is the weaker response from the heater and AC.

 

After reading this thread I turned off ECO mode and drive in normal mode and found my mpg went up. Amazing! I assume its because I am on the gas pedal less because there is more power to get up hills and up to speed from stop.

 

The major factor in fuel consumption is driving style. How one reaches cruising speed (stomping on the gas, or reaching it smoothly and progressively having the ICE work in an efficient RPM) and keeps it, makes the major difference in MPG. How often and in which way one brakes and how long can one keep the car moving smoothly keeping in the flow of traffic, will also affect MPG.
The modes affect only marginally the MPG, so whatever mode makes you achieve the conditions above will do. PWR mode tends to keep the ICE spinning when releasing gas for faster response when accelerating again. This can have a visible MPG hit for some and not for others (e.g. if you drive at constant speed for 90% of the trip, the ICE is on anyways...).
Try the mode that suits you best and you like the most, and focus "on the flow" - that will essentially define your MPG (together with other factors out of one's control - e.g. temperature, weather, traffic, route, etc.), not the mode you are in.

 

I just got an '11 Prius II and was told by the dealer to keep it in ECO mode for most driving so I'd like to see a consensus of which mode is optimal for best MPG. Unlike you, Tony Reiner, I won't be drag racing although if that gorgeous GTO is part of your heritage, I understand why you do. I liken my Prius driving experience thusfar to that of my former '97 Taurus which had a sublime ride and crisp, though certainly not sporty, steering. That's really a complement because I loved that '97 Taurus. But since I bought this Prius for MPG, I want to keep it in the sweet spot for that. Sounds like there are varying opinions here on this and I'd like to know who's right.

 

Try ECO for one tank, Normal for the next, hopefully under very similar conditions, try to drive the same style. That's the simplest way to sort out your opinion.

I switched over from ECO to normal and my mileage doesn't seem to have changed. I track every tank. MPG has actually improved since the switch, but so has the weather, likely a factor. All-in-all I see no difference.

ECO I find frustrating for pedal feel, just too much pedal travel required for a decent reaction.

 

As a new Prius owner (just picked up this weekend!) this is a great tip. I've just been in ECO mode so far and will try Normal for the next tank. From what I've read it sounds like ECO works well for those really hot or really cold days.

 

I stay in Normal mode all the time and still avg 52-55mpg..tried eco and hated it..