10mph too fast for EV mode? 2012 Prius 3

When you say warmed up do you mean at or above 153F? That is warmed up and it generally will not happen just parked in the driveway.

I believe you have to hit Stage3 in the warm up cycle before you can reach the 25mph limit.

http://priuschat.com/forums/gen-iii...-discussion/76501-gen3-warming-up-stages.html

 

For the 2010 (I haven't verified these with the 2012 yet):

Engine coolant below 68F: EV not available
68F < T < warm (I didn't personally verify the 153F the F8L lists): EV max speed 9 mph
warm < T : EV max speed 25 mph.

Warming up while sitting, in ECO mode with climate control off, my ICE shuts down at about 103F, so it doesn't get warm enough for the higher speed EV mode.

 

Actually, it's a little more complicated, fuzzy; you can only EV up to 9 mph and at 68°F or greater if you hit the EV button before the engine turns on. Once the engine is on, you can't enter EV mode until (typically) 40°C, which is also where the engine will turn off for the first time. After that, F8L is right - the coolant has to be 70°C (I use °C because it's much easier - the major points of interest are 40°C, 70°C, and approaching 100°C, rather than 104°F, 158°F, and 212°F).

For you normal people that don't have special instrumentation to monitor your engine coolant temperature, it would take a mile or two at highway speeds or about 4 miles in city traffic to reach the full operating temperature, on a nice day (say 70°F). Very roughly, anyway. And outside temperature will have a HUGE effect on how quickly you reach full operating temperature; in particularly cold areas, it is not uncommon to be unable to reach full temperature on a 20 or 30 minute commute, I hear, especially if you're using cabin heat.

Also, you'll never be able to get to 25 mph in EV for the first few minutes after the car is turned on, no matter if the engine is warm or not; it still runs through a (shortened) warmup cycle anyway.

The bottom line is that the car takes care of itself; this means that you won't always know why it won't go to 25 mph in EV, but it decides that it's not good for it at the time and will refuse. Of course, there aren't many times where it will improve your fuel economy to use EV either, so you're better off just using it rarely - it's mostly just a gimmick.

 

EV mode is not for driving. It's for moving the car in the driveway. Otherwise it's pretty much useless as implied above.

Brag about your -average- mileage, not EV mode.

 

Actually you can use EV mode a lot. We were talking about it a while ago. http://priuschat.com/forums/gen-iii-2010-prius-fuel-economy/108080-using-electric-vehicle-mode-first.html.

I use it at stop lights to get up to speed which is a big gasoline usage spot for cars. Use it for the last mile cruise home. Use it pulling into parking lots or garages. It is oddly and mildly erratic so it is interesting to see the explanations above on why it works sometimes but not others in what seems like similar situations.

But end of the day, having the mini-me EV is fun and fuel saving feature and technique.

 

Complete agree with you, should have the penny (oops pennies are gone in Canada) on the switch by not having it

 

I, too, have noticed that EV mode is sometimes unavailable, even after the ICE has surpassed minimum operating temperature and the traction battery shows plenty of charge. Perhaps this is due to traction battery temperature, although I really don't know. It was reassuring to to me to observe this behavior in each of our three Gen 3 Prii and is, therefore, not a defect in one. I accept that Toyota engineered efficiency and hardware safeguards into the Prius technology that I don't fully understand and doubt this is a defect in all Gen 3 Prii. Perhaps someone on this forum will post a better explanation for this normal behavior. Many experts on this forum will remind us both that consuming electrons, that must be replenished, does not always provide the best fuel efficiency. If your family is anything like mine, they may already have grown tired of hearing you brag about Prius technology, anyway.

 

I forgot to mention that.

When waiting at a nearby stoplight before reaching 40C, I often use EV to delay warmup until the light changes. Since EV won't work during warmup, I must turn the car off, then back on, then hit EV before the ICE can restart. This keeps the ICE off until the light changes and I break the 9 mph limit.

I believe the 40C threshold is specific to ECO mode, and the Normal mode has a higher threshold. But I don't use Normal mode enough to verify this.

 

EV mode works great in reverse.

 

Hahahahaha...good one

 

EV drive mode is off back to normal when you floor the accelerator pedal. I think the car is protecting itself not to put too much load on the electric motor.

Hmm... What if I floored the pedal in reverse....? What would the car do? Disable EV in reverse...?! Ha~

 

I use the EV mode a lot. I use it in my neighborhood. I use it going to work on this 1 mile stretch of road where the speed limit is 40 MPH. I get it up to speed and golf cart it the rest of the way. It really does help.