EV the warm-up and preserve charge for next trip?

if i understand correctly, yes. when i'm going further than my 15-17 ev miles, i start out in ev. at speed limit, i don't spike accelerator, i hit ev/hv button which kicks in ice warm up. i also shut off eco mode because it's hard to run on ice in hv unless you really throttle it. it likes to stay on battery. then, as i'm driving, i switch from hv to ev and back and forth as conditions allow for optimum use. if i want to preserve ev, i have to keep the throttle down and still it uses up a bit of battery. you can run ev intentionally, but it's tricky to run ice all the time.

 

Whether its in ECO or Normal, makes no difference as far as EV or HV and electricity consumption. ECO and Normal work the same way it would on a no-plug Prius (just a remapping of the throttle response)

In EV mode, you would only dip into HV when (1) you run out of EV range, (2) you depress the accelerator enough so that the HSI bar gets into the PWR section, or (3) your climate control is on and requires heat (which comes from the engine).

In HV mode, the car will draw charge the same way a no-plug Prius would. However, if you have any EV range remaining, it will preserve that EV range. So if you have 2.0 EV miles showing and you're driving around on HV, you may see it dip occasionally, but the car will replenish the EV range (to whatever it was when you switched to HV) when it can (either through regen or utilizing the engine when its on and power demand is low). Many refer to HV mode as CS (charge sustain) mode.

 

i'm not seeing that tracksyde. when i leave in hv mode on a 30 mile trip to my fathers every thursday, i start out with about 15+ eve range and get to his house with around 12-13 ev range. and that's aggresively using the throttle to keep it out of ev.

 

bob, track has it right on #1. on 2 + 3, he is right that they are the same, i just find it easier to keep the engine running with eco off because of throttle response. unfortunately, i can't compare it to a standard gen III but compared to my gen II, it seems harder to get the ice to fire no matter what mode you're in.

 

I used to think that I could deplete the projected EV miles while running in HV at slower speeds, but am now not sure. I now think that if one has projected EV miles available and presses the EV/HV button to go into HV, the car can and will use EV and drop the EV miles projected if conditions merit the use of electricity, particularly at slower speeds. If one ends the trip while the EV miles have dropped, it will seem like the car has used up EV projected miles while driving in HV. However, if the trip continues longer, and there are conditions which generate electricity, such as going downhill or perhaps having more ICE power in the "good" range than is needed to drive the car, then the EV projected miles seem to go up to the point where the EV/HV button was pressed to put the car in HV.
For me, this raises the question whether you can really use up projected EV miles on a long HV trip, even if the HV trip is slow. Does anyone have an answer?

 

are you saying it records ev level when you hit hv and works to try and keep it there? it can't use up some ev after you hit hv and then at some point decide to start replenishing until it gets back there. unless it has a min/max level but what would be the point of that?

 

Yes, I believe that if some projected EV miles are showing when the EV/HV button is pressed to go into HV, the car records that EV level and works to maintain that level. The point is to preserve EV miles so they can be used later, perhaps for the slow speed miles from the highway to home.

 

It is not my experience that the car works to maintain a certain level of charge.

I find that at about 35 mph in HV with a full charge, I consume some EV range but get HUGE (as much as 90 mpg) mileage. At above 50 mph in HV with a full charge, I tend to preserve my EV range and can even increase it by coasting down hills and some braking. The difference is wind resistance which requires greater use of the accelerator pedal. In such cases I get between 55 and 65 mpg. The trip gets better overall mpg when I use up the EV range at the end.

The EV range available is not like an odometer. It is an indicator of the charge remaining. Even at low speeds, I can extend my EV range by using gentle acceleration and coasting when I see a red light ahead or when there is even a slight down grade in the street ahead. Speeding up and then braking for the red light uses up more range.

 

it's funny how we all see it a bit differently. we need someone with an engineering backround to do some real objective scientific, testing. hmmm, i wonder who here might be qualified to do that...

 

I don't think that to be strange. We report what we observe on one hand and we report what we believe on the other. Those who read what we report can evaluate what they see accordingly. Observations can be replicated. Beliefs are just that. If there seems to be supporting evidence, they may be more valuable. Otherwise, they are interesting reference points for our own observations.

In any case, I feel that we benefit from sharing and I am grateful for that.

 

FYI,
Following is an interview article with Toyota engineer.
tips to increase ev range (Japanese language)

summary is...

• PiP preserves its ev range when it changed to HV mode.
• For example, if the ev range was 10km, it maintains the ev range between 9.8km and 10.2km.
• When driver is approaching a downhill and would like to increase the ev range, switch PiP to EV mode, then drive the downhill. The ev range will be increased, for example, 10.2km by regeneration.
• When PiP reached a flat road, then switch it to HV mode again.
• The preserved ev rage is now 10.2km instead of previous 10km.

Enjoy,
Ken@Japan

 

Like CraigCSJ said, it could take a while for HV mode to get it back to that "saved" EV level. I can confirm I've seen this behavior twice in the past few days. In both cases, I drove to Los Angeles and back (100 miles round trip).

On my return trip on Tuesday (which took 2 hours to go 50 miles in the carpool lane), I was on the freeway for about 20-30 minutes before it got back to the level it was at when I switched to HV mode.

I've also seen in the past where I'd switch to HV and it would not get back to the original EV range. However, I'm sure its because those trips were much shorter and did not have any opportunities to regenerate/replenish the EV ranged used while in HV.

Its good to see Toyota's own engineers echoing our own findings here (stacking EV range).

 

what if you charged up and drove 100 miles at 20-40 mph in eco mode?

 

thanks ken! i'm going to test this today. 60-80 miles of city/highway with some a/c thrown in.

 

what if you don't switch to ev on the down hill? will it charge the battery but then use it up in hv so you're back to the same level as before you started downhill?

 

I believe the answer is yes, and the MPG at that time will be higher than it would if you switched to ev going down and "captured" more electricity. Although since Ken said there is a "range" it returns to (+ or - .2km ) it might only go back to a level .2km above the point where HV was turned on.

 

Ken seems to be the best source of information about our cars. I certainly rely on that.

My frustration has been that if I "just drive" in EV mode I never seem to get near the range which is predicted by the car. I have not found a way to measure this exactly but I have been getting somewhere between half and three quarters of the predicted range. When I started concentrating on not accelerating sharply and coasting when I had no need of applying power, I noticed that the EV range increased. I was getting home with three miles remaining on trips which were "nip and tuck" whether I would make it home before the ICE started up. And I am still driving right at the local speed limit. So, I conclude that we cannot rely on the car to hold the EV range for us. We must do our part to do that even in HV mode.

Sadly, most drivers expect to "just drive". They will get good results with the PiP, but not great results.

 

today, i started out with 15.5 ev range. i switched to hv at 15.3. i drove 33 miles and the ev range was 11.2. i switched to ev and drove until it was 7.5. then i switched back to hv and drove 30 miles. it was down to 5.4 and when i stopped at a light, the ice came on and ran until the ev range went back upto 5.9. i then switched to ev and drove home. pulled in with 2.2 on the range. not sure exactly what happened, but it did seem to be trying to preserve range at times, whereas, in the past, i thought i was the one trying to preserve range. it's still very confusing.