Confused: Why does estimated EV miles keep dropping?

Since you've had your PiP with about as many miles as I have, 1500 miles, allow me to share my experience:

I drive the same 53 miles on the freeway to work. I use cruise control every time I get on the freeway. I always soft peddle the accelerator. When I first got the car, it lasted me 10 days going to and from work before needing filling up. Now I cannot get all the way to work and back for 10 days on one tank. I only use the heater when the ICE is on so that it wouldn't drain the battery. "So it is obvious to me that I do not have the same energy to use as when I first got the car." Or is it? Let me give you more information.

The first 10 days of ownership, I drove slow. It was a new car, I wasn't familiar with it. I was playing with all the settings and electronic gadgets. I was honked constantly from behind. Temperatures were warm, but not enough to use AC. When I filled up, I got 80 mpg. Average speed indicated was 29 mph. (Please don't flame me, most of this slow speed was horrible horrible traffic. )

The next 7 days of ownership, I drove faster now that I was familiar with the car. It rained. I had to use the defroster. I had to use the wipers. Temperatures were no longer 80+, now at 60 or so. I used the heater. 7 AM is now dark. I had to use my headlights. Going home, at 7 AM, it is also, now dark. I need to use my headlights. I only made 7 days for the my next fill up at 70 mpg. Average speed indicated was 37 mph. Oh, and California changed to the cheaper winter formulation of gas earlier this year due to rapidly rising gas prices.

Is it still obvious that my car has less energy to use as new? Understand that, everyone agrees that >3 miles difference in EV range is a big deal but you'll have to provide more context before it becomes "obvious."

 

den, i have the same problem as you. the car doesn't go as far as it did on the same route as before with similar driving style. i'm down from 16.5 to 14.4. i'm attributing it to cooler weather (although, only 50's and 60's) and the fact that i come home in the dark with my headlamps on. could it be a battery problem? i won't know until next spring.

 

Note that headlamp drain is pretty significant.

 

would not be surprised, but would like to know how significant. i don't see many others mentioning it. misery loves company you know!

 

Yesterday, I had to make an emergency trip to my mom's home, 6.5 miles away. I took the highway and surprised how capable PiP is at highway speed as well. I went 55-60 mph. I made it there with full electric.

On my way back home, I noticed the elevation is higher (just noticed when driving on battery now) and using the GPS estimated miles to home, I figured I will need to use gas. I used it on an incline that is an overpass over another highway. In total, I think I got about 12 EV miles as I used gas for about a mile.

If I drive at lower speed (city driving), I get 13-14 EV miles. Perhaps more but I have not exhausted my EV miles in city driving alone. I have been using it at highway speed because I had extra.

My point is, the initial estimated EV miles is probably based on a mixture of city and highway. When you use the EV miles purely on the highway, you will get shorter miles. Plus the weather changes (and tire pressure?) and other factors may affect it as well.

If you cannot charge at work, you may want to use some gas on your way to work by switching to HV mode strategically. Use the remaining EV miles on your way back home strategically again.

 

i think you're missing the part of his post where he says he used to go x distance, and now it won't. even tho it's the exact same drive.

 

I did mention the weather and tire pressure changes. Head and side winds can take down the range.

Perhaps, there is a battery break in period as well. On the other hand, I doubt PiP can do 14.2 miles at highway speed, as he claimed.

 

And many others have pointed out that range will fluctuate depending on many factors. Even in my Corolla I can take the same exact trip every day of the year & my average mpg will be different. There are so many factors that I just wish the OP would be open minded & understand the variables. Does every Duracell battery last the exact same time for the same toy? No, of course not. Are we understanding better now?

 

perhaps, but i made the same commute 5 days a week since april 26th and it was always within .1 - .2 miles until late september/october.

 

agreed. 'highway speed' connotes high speed. i don't think you can go 14 miles even at 55 mph. unless it's all downhill. maybe he sets the cruze to 40.

 

Can I suggest a simple diagnostic?

Another PiP owner meet up with Den at a charging station. Both top off their battery and then one follow the other on a 20 mile route and see if EV on both vehicles performs the same.

 

i would love to see anyone do that.

 

Den,

You don't need to respond to each post, just click "like" to acknowledge.

 

And you live up north so the first reason would be that's when temps are cooler, very simple to see. Every Prius owner sees lower mileage in cooler weather. During the warmer dry months my tanks average around 52-53 mpg & when it cools down & the rains come my tanks drop to 45-48 mpg & these are calculated numbers. Read through any of the threads about winter dropping in winter to learn more.

 

excuse me, but i've been an owner and member since 2005. i know all about cold weather and rain. if you had read my post, you would already have seen that i was attributing the drop to the posibilty of cooler weather. although if you're trying to compare it to your regular prius, that's a reformulated gas issue at this point. my mpg's never dropped in 55-65 degree weather.

 

Mine do.

 

Hi Den, thanks for the additional information.
I didn't see information about where you live? Colder temperatures don't just cause lower efficiency due to increased HVAC usage. Air density increases as temperature decreases, which will cut into efficiency.
Others have also mentioned increase in use of lights, although I am not sure how much of an affect that really has, it is negligible in cars with larger batteries, but may be more noticeable in the PiP.

Does the PiP show you your watts per mile? If so, that may give you a truer picture of if your battery is loosing capacity, or if, as I suspect, you are using more energy to drive the same route.