Ev / HV Question

No one has really answered your question exactly right, nor given you a suggestion as to how best to handle the trip you had. Allow me to try....

First, when HV mode is engaged for the first time (cold engine) the engine is warmed up under a "low load" to protect it at cold start and for emission purposes. So EV power (and range) is used to actually drive the car during the warmup. If you continue to drive in HV mode, after the warmup cycle, that lost EV range during warmup will be restored!

The problem with your choice to make a 2.5 mile drive in HV mode was that it consumed gas and battery, without benefit. You basically wasted gas warming an engine, then did not use it, and still consumed EV range. And such a short distance was not be long enough to allow EV range to be restored from the engine warm up.

The better choice would have been to drive the first 2.5 miles in EV. Then later that day, since you couldn't charge, and I assume would be driving beyond the remaining EV range, use a combination of HV/EV driving. And if the HV driving was long enough it would restore the EV range lost to that warmup cycle. If the driving you had planned later was within you EV range, there would be no reason the use HV mode.
Make sense?
You gotta consider what mode, and when, would be most efficient if the total drive is beyond EV range, and when a warmup cycle would be most likely to be restored.

 

If you drive with a light foot on surface streets the csr will pull charge from the traction pack irrespective of if you are in EV mode or HEV mode

My PIP does some interesting things. When I drive down a long slope going home from work I can rege up to about 1.4 miles of range. The battery charge indicator doesn't change from HEV to EV until the EV range gets to .8 miles. If the charge doesn't get that high the battery charge indicator doesn't change.

As the EV range is used up the car stays in EV mode and indicates .1 miles EV range until a couple of bars are used on the HEV batters display.

 

Good evfinder, Thanks for detailed info, .

 

True, When the ICE is warmed up. Nothing new here. Thats the way all Prius' work. It was called Stealth mode (in the good days) and it happens below 41 MPG in the Gen II and below 46 MPH in the Gen III (and PIP in HV)

Well documented in the owners manual. HSI and HV/EV battery level indication change.

 

I agree with 9G about the warmup using EV. After warmup has finished, the car will attempt to regenerate back to the set EV miles (what it was when HV mode was entered). Driving 2.5 miles is not long enough to regenerate the EV miles lost to warmup w/o a lot of regen braking.

Another thing is that if you drive on electric only (below the midline of HSI), EV miles will be consumed. However, the Plug-in will attempt to regenerate back to the set EV miles only when driving hard enough to have the ICE fire.

 

Always try to use up the Battery Miles before you get to a charging location.
If the trip is less than the available Battery Miles, try to stay in EV, by not going into the Power zone that would turn on the ICE.

If you need to go over 62 mph or if you need Heat, the ICE will start.
When the ICE first starts, it warms up. It should not race the engine.
If the ICE is needed and not warmed up, it starts and the Battery assists to move the PIP.
After the ICE is warm, its excess energy will flow into the battery.

Use HV if you want to save Battery Miles. When you switch to HV, if the ICE needs to warm up, the Battery is used. When warmed up, the ICE will replace the Battery Miles that are used.

However, driving 100 miles is way beyond the Battery Miles and you should expect to get the 50-60 mpg using the ICE.

 

During warm-up the ICE doesn't "race" . Just the opposite, in fact. Racing a cold engine is never good. It warms up just above idle and so the car still relys on electric power until the ICE is warmed up.

Making the 2.5 mile trip in EV only was a good choice. And your plan after that sounds smart too.
The EV range you had left is less than 10% of the travel distance and would make a difference of maybe 6 MPG, but use is all before your next charge.

 

I bought my car 2 months ago. The original EV was 11.7mi. Since then, the EV drops everyday to every other day by 0.1 EV. Now my EV is 9.2mi after overnight charge. Is there a way to improve the EV? I saw some charts about removing the negative lead on the battery x few seconds and then replace it. Does this work? Thanks.

 

it's the law of averages, go 25mph consistently and your EV will go up

 

That's only an estimate, just ignore it.

12.9 was the estimate displayed before I pulled out of my garage.

16.1 was when the engine finally started while on my morning commute.

16.6 was the total distance traveled. There parked at work, the average was still at 999 MPG.

 

It'll use some gas but not a bunch. If you can't avoid it, consider it maintaining the gas engine and the fuel tank (to avoid going stale). All the plugin hybrids need to use the gas engine once in awhile. You'll be doing it when you actually need it, justifiably.

Under the EPA test cycle, 0.2 gallon of gas was used during the 8 miles long high speed test. That includes the amount of gas used for warmup plus the remaining drive to complete it. I would think just warming up the engine would use much lower than 0.2 gallons.

 

I wonder why Toyota doesn't attempt to better explain the start-up EV miles after a full charge. I am charging at least once a day.

 

EV miles displayed has no way to know what speed you're traveling until you complete your driving so that's why it's a estimate based on past speeds you were driving and it's an average of all your driving speeds (like ERA in baseball)

 

the higher your speed traveled the less EV, lower speed more EV