Confused: Why does estimated EV miles keep dropping?

Very simple, the car was learning the range with the larger wheels on it. Even with light weight wheels the 18" tires are much wider & heavier & will hurt your mpg & EV range. The biggest trick is to remember that the EV range is an estimate & nothing more. It's like you getting used to traveling 500 miles per tank of gas but suddenly you have a tailwind on a long trip & your gas range to empty will adjust the entire tank of gas as you use fuel at a slower rate then the computer has guessed is normal. The range to empty tank works much the same way. The most important thing is to just measure your actual EV range & not worry about what the range says. If you travel down a hill your range will increase too.

 

A parallel thread needs to be started. "Confused: Why do my actual EV miles keep dropping?"

 

movie is right. if he's had the 18" wheels all along, they are not contributing to actual decline.

 

We don't know the actual algorithm enough to determine that. I have noticed that using mixed "ev boost" mode the car doesn't see to calculate that into the average as much. On the weekends I go out early for errands and drive on city streets very slowly which seems to help a lot. My average display still shows 13.1. On my commutes I barley get 6 miles of pure EV, (the ratio screen doesn't show "ev boost" miles).

 

We always talk about the wheel size all the time, but I think the tire that's mounted on that wheel also is a biggie.

I don't think it's a weight issue as must as it is a gear ratio issue.

Once the tire is mounted.... what is the final diameter of the tire / wheel combination?

Low profile tires mounted verses semi low, verses normal?

I think the prius is engineered to run 15 inch wheels.
The size of the alternators all turn at different rpms if the tire/wheel diameter changes.

The chevy Volt and tesla work best with bigger tires, so it's not just the tire size alone per Se, but what the alternators optimum Rpm range verses load that comes to play.

Does this make sense to anyone else or am i totally missing it here?

Alan...
Sent with Tapatalk 2

 

You are totally missing it. As the wheel size gets larger the weight moves out farther from the hub & this affects mpg, braking & acceleration. Tires also play a huge role in these areas too. The larger wheel uses a wider, heavier tire that will get worse mpg,hurt acceleration but braking will improve. The key is to keep the diameter the same to keep the speedometer accurate. The Prius will get the best mpg with 15" & the ability to use a LRR tire will also help a lot.

The Volt & Tesla along with any car will accelerate faster with a smaller diameter wheel. There have been results done with different cars proving this fact. The gearing issue is calculated for all cars with an idea of what the over all tire/wheel diameter will be.

 

I'll gladly take it back if that is the case! I hope you're all right. Otherwise it's rather depressing after fully charging the car and you just drive down the street and your "estimate" says 6.9 miles already! And I know "actual EV range" versus "EV Estimate" is different. But the estimate seems to be pretty accurate to the "actual."

 

my estimate is very close to actual, i think because i drive the same route a lot with same driving style. i hope the warm weather comes soon! (tho, it will be a lot sooner for you than me )

 

Movie, does your car give you a reading for Watts/mile? If so, as long s it is accurate, that number has most likely increased (or if it reports miles/kWh, decreased). This would reinforce the idea that the battery has the same capacity and there is some external factor at play (tires, weather, etc).

 

Hi all, I have not been on in awhile due to drama with a contractor who stole my deposit money. If you need a shed, guesthouse, poolhouse built DO NOT USE : "LA SHEDS" which he now changed to "LA STUDIO SHEDS" (dot com) his name is KEVIN SMITH, he had my wife and I trusting him up until we gave him a $6500.00 material deposit. He was to build us a finished pool changing room right next to our pool. Sorry just trying to save people a huge headache and despair and get the word out anywhere I can. (he never brought over one piece of wood) and he does not return calls or texts - just goes straight to voicemail. I gave him the deposit on 12/13/12.

Anyway, back to PiP world. If I scroll up I know I will find someone who said check the air pressure - when it's cold that person told me that they would lose air more quickly. As soon as I did this my PiP started cruising like it used to. I was down to 31/31 psi in the front and 30/30 in the rear. Right after I put 35/35 PSI in the front and 32/32 PSI in the rear I was able to drive from my Father-In-Law's house to my house (12.5 mile distance) all in EV mode. So it definitely had everything to do with rolling resistance for me.
So before that I was down to 8.9 EV range (based on past driving of course) but I'm still wondering why even after the problem solved and I can surely say I can drive an ACTUAL 11 to 13 miles in EV mode, Why did it only go up from 8.9 to 9.0??? (EV range estimate) I thought surely after seeing and feeling the results it would go back into the 10.0 to 10.5 range (where it used to always be for the longest time - with same setup, same route, same conditions, same everything)
BTW - lately it's been super cold (39 to 50 degrees outside temp when I start my day) and my EV range now went back down and even lower now to 8.8 EV estimate. I want to cover up the screen it's kind of depressing! LOL!

 

My EST. MPG used to be between 15.2 and 16.2 Now it is 11.8. COLD WEATHER. Do not worry, when it gets warmer it will get better again! ENJOY! Your car.

 

interesting note: when it was 23 degrees out and I charged the battery my SOC was 83.7% this morning (last night 60 degrees when I charged) my SOC was 84.7%

 

OP, don't worry. Also, the estimate changes slowly, so that's why you didn't see it rise immediately.
Actually that "cover it up" idea sounds brilliant

 

i am regularly driving 13-14 miles ev, but my full charge is stuck on 12.3, i think there is more to it than history. i have never run out anywhere near 12.3, nevermind something lower that would make 12.3 some kind of running average.

 

Seems like it would be very hard to get an accurate read of capacity left if it's simply monitoring voltage?
Frequent load test would waste the battery life.
Especially lithium is tricky since it holds its voltage so well until it gives up the ghost.

Alan.. Sent with Tapatalk 2

 

that's why the engineer's opted for the ev range instead of battery capacity.

 

Seems like determining that is the same thing?

Seems anything that changes internal battery resistance "heat' affects capacity or longevity curves.
Ambient temp or quick or recent heavy use all skews or rather affects those variables.

All I'm saying is it seems its best to treat it like the gas Guage.
We all know expected distance from gasoline is all vulnerable to many variables and so can never be trusted unless variables all stay the same.

Likewise It's a dicy game determining if the battery is the part of the equation that's deteriorating or if it's other variables.

I wouldn't be too concerned until we get warmer weather.
Even then, too hot can be bad too.

Tesla has a nice idea in that they bathe their batteries in coolant that cools or heats as needed.... Prob not necessary but nice to keep consistent expectations of performance.



Alan.. Sent with Tapatalk 2

 

agreed. i think we look at it differently because we have the back up ice. if it was a pure ev, we would be looking for a recharge when the blinking light came on or sooner. but as it is, we're just trying to figure out how it determines the range number. for dte on gas, i assume it's a pretty straight shot at past average mpg's x gallons available. but ev range is not past ev miles average time kwh available. and then there's the mixed ev/hv the software has to deal with.

 

I've seen my SOC range from a low of 84.3% to 85.4%. Car typically finishes charging around 2:30am, but I don't get into it until around 9am. Temps around here have been between 35 and 40 while charging, and around 46 when I get into the car.

 

I see some of you "experts" killing newcomers for trying to explain their experience with the Plug-in. I'm sorry but i'm a new owner myself and will tell you when i first got the car a couple of months ago i would charge my battery for 3hrs and get 13.5 miles....A full charge now only gets me 9.5 miles. It hasnt gone up, only down. I recently tracked my milage on EV and sure enough at 9.4-9.5 EV went off. Didnt matter if i was driving 25mph or 50mph. Its just not right. I thought i was going to get 10-15 miles on EV and after a couple of months i'm under 10. Now i do live on the east coast and the weather is finally warming up so i'll see what happens. But to hear other people say they are getting 15+ on EV tells me either they're lying or something is wrong with my battery. I baby this car so its not my driving. Should i take it in to Toyota?